| 1. |
- Cervin, Anders
(författare)
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Neuropeptide Y 16-36 inhibits mucociliary activity but does not affect blood flow in the rabbit maxillary sinus in vivo
- 1992
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Ingår i: Regulatory Peptides. - : Elsevier BV. - 1873-1686 .- 0167-0115. ; 39:2-3, s. 237-246
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Tidskriftsartikel (refereegranskat)abstract
- Recent investigations have shown neuropeptide Y (NPY) to be present in the rabbit maxillary sinus, and NPY is known to be released upon sympathetic nerve stimulation. To study, in vivo, the effect on mucociliary activity and blood flow, NPY 1-36 and some of its analogues were injected intra-arterially. The effects of the Y1/Y2 agonist NPY 1-36 was compared with the ones of the Y2 agonist NPY 16-36, the Y1-agonist [Leu31,Pro34]NPY and the Y1/Y2 agonist peptide YY. Mucociliary response was recorded photoelectrically and expressed as a percentage of the basal mucociliary activity immediately prior to challenge. The effect on blood flow was measured with laser Doppler flowmetry and expressed as a percentage of the mean blood flow during the 60 s preceding challenge. NPY 1-36 and NPY 16-36 both reduced mucociliary activity dose-dependently at equimolar dosages (0.024-1.2 nmol/kg). The greatest effect was seen after the highest dosage tested. NPY 1-36 reduced mucociliary activity by 14.6 +/- 1.8%, and NPY 16-36 by 13.2 +/- 1.4%. At the highest dosage tested the Y1 receptor agonist [Leu31,Pro34]NPY did not significantly reduce mucociliary activity, whereas PYY reduced mucociliary activity by 15.0 +/- 1.8%. Injections of NPY 16-36 had no effect on blood flow whereas NPY 1-36, [Leu31,Pro34]NPY and PYY all reduced blood flow dose-dependently. Maximal decrease was seen at the highest dosage tested and was 47.1 +/- 5.4%, 70.4 +/- 7.4% and 58.2 +/- 8.4%, respectively. These findings suggest the mucociliary effects to be mediated via Y2 receptors whereas blood flow is regulated via Y1 receptors.
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| 2. |
- Duan, R D, et al.
(författare)
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Stimulatory effects of human pancreatic polypeptide on rat pancreatic acini
- 1985
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Ingår i: Regulatory Peptides. - 0167-0115. ; 12:3, s. 215-222
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Tidskriftsartikel (refereegranskat)abstract
- The effect of human pancreatic polypeptide (HPP) on rat pancreatic acini has been studied. It was found that HPP stimulated amylase and lipase release from the acini. The secretory response of acini to HPP was dose-dependent in a sigmoidal fashion. Between 10(-9) M and 10(-8) M concentration of HPP there was a slow increase of enzyme release to about 40-60% over basal release. At concentrations of HPP above 10(-8) M there was a rapid increase of enzyme release, amounting to 4-6 times over basal release at 10(-6) M concentration of HPP. The potency of HPP compared to other secretagogues at 10(-7) M concentration was 45% of CCK, 60% of carbachol and 75% of secretin. HPP did not inhibit the effect of CCK, secretin and carbachol on amylase release. The amylase release stimulated by HPP was accompanied by an increase in 45Ca2+ efflux. Atropine or dibutyryl cyclic GMP did not influence the effect of HPP. It is concluded that HPP stimulates the release of enzymes from rat pancreatic acini and that Ca2+ may be a mediator for this secretion.
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| 3. |
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| 4. |
- Grundemar, L, et al.
(författare)
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Neuropeptide Y : prejunctional inhibition of vagally induced contractions in the guinea pig trachea
- 1988
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Ingår i: Regulatory Peptides. - : Elsevier BV. - 0167-0115. ; 23:3, s. 309-313
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Tidskriftsartikel (refereegranskat)abstract
- The effects of neuropeptide Y (NPY) on the contractile response to vagus nerve stimulation at different frequencies was studied in an isolated tracheal tube preparation from guinea pig. NPY had no effect on basal smooth muscle tension or on the contractile effect of carbachol, but inhibited vagally induced contractions in a concentration-dependent manner with a greater inhibition at low frequencies than at high. We suggest that the effect is exerted prejunctionally.
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| 5. |
- Grundemar, L, et al.
(författare)
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Neuropeptide Y suppresses the neurogenic inflammatory response in the rabbit eye; mode of action
- 1993
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Ingår i: Regulatory Peptides. - : Elsevier BV. - 0167-0115. ; 43:1-2, s. 57-64
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Tidskriftsartikel (refereegranskat)abstract
- Ocular injury in the rabbit causes miosis and breakdown of the blood aqueous barrier (aqueous flare response, AFR), reflecting a sensory nerve-mediated inflammatory response, elicited by the release of tachykinins and calcitonin gene-related peptide (CGRP) from C-fibers. Neuropeptide Y (NPY) occurs in sympathetic fibers in the eye. The study was designed to examine whether NPY and related peptides interfere with the inflammatory response to ocular injury in the rabbit in vivo. The isolated rabbit iris was studied with respect to NPY binding sites and second messenger coupling. The AFR and the miotic response to a standardized injury (infrared irradiation (IR) of the iris) were suppressed dose-dependently by NPY (0.01-1.0 nmol) injected intravitreally 30 min prior the trauma. The treated eye was compared with the contralateral eye, which received 0.9% saline and IR. The Y1 receptor agonist [Pro34]NPY, the Y2 receptor agonist NPY 13-36 and the structurally related peptide YY (1 nmol each) suppressed the AFR in response to IR. Injection of either NPY or the Y1 and Y2 receptor agonists (0.3 nmol each) suppressed the AFR evoked by exogenously applied CGRP (0.15 nmol). Saturation studies with 125I-NPY revealed both high and 'moderate' affinity binding sites in the iris. The Bmax values were 26 and 321 fmol/mg protein, respectively. NPY suppressed the forskolin-stimulated adenylate cyclase activity (IC50 value 19 nM). NPY did not affect basal or noradrenaline-induced accumulation of inositol phosphates in the iris. In conclusion, the rabbit iris seems to be rich in NPY receptors linked to inhibition of adenylate cyclase activity.(ABSTRACT TRUNCATED AT 250 WORDS)
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| 6. |
- Grundemar, L, et al.
(författare)
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Unlike VIP, the VIP-related peptides PACAP, helodermin and helospectin suppress electrically evoked contractions of rat vas deferens
- 1992
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Ingår i: Regulatory Peptides. - : Elsevier BV. - 0167-0115. ; 40:3, s. 331-337
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Tidskriftsartikel (refereegranskat)abstract
- We have compared the effects of vasoactive intestinal peptide (VIP) and of the VIP-related peptides pituitary adenylate cyclase activating peptide (PACAP) 1-27 and 1-38, helodermin, helospectin I and helospectin II, on the electrically evoked twitches in the isolated vas deferens of the rat. While VIP was virtually without effect, PACAP 1-38 suppressed the electrically evoked twitches effectively and in a concentration-dependent manner (pIC50 value 7.5). The naturally occurring N-terminal fragment PACAP 1-27 was less effective than PACAP 1-38 (Imax values 37.2% suppression compared to 76.5%) and less potent. The C-terminal fragment PACAP 16-38 was virtually inactive. Also helodermin and helospectin I+II suppressed the electrically evoked twitches effectively and in a concentration-dependent manner (pIC50 values 6.9; 7.2; 6.8, respectively). The three peptides produced similar maximum reduction of the twitches (74-80%). The findings suggest that PACAP, helodermin and helospectin suppress the electrically evoked contractions in the rat vas deferens via receptors distinct from VIP receptors.
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| 7. |
- Hellstrand, Per, et al.
(författare)
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Role of vasoactive intestinal polypeptide (VIP) in the neurogenic vasodilatation of the portal vein in the rabbit
- 1985
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Ingår i: Regulatory Peptides. - : Elsevier BV. - 1873-1686 .- 0167-0115. ; 12:4, s. 309-316
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Tidskriftsartikel (refereegranskat)abstract
- A coarse network of nerve fibres displaying immunoreactivity for vasoactive intestinal polypeptide (VIP) was found in the wall of the hepatic portal vein of the rabbit. Electrical field stimulation of the rabbit portal vein in vitro, in the presence of adrenergic and cholinergic blockade, caused a marked relaxation of the vessel and a release of VIP into the perfusate. Addition of VIP to the tissue bath elicited a concentration-dependent inhibition of the mechanical activity of the portal vein. The results suggest that VIP containing neurones might participate in the non-cholinergic, non-adrenergic vasodilatation of the portal vein in the rabbit.
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| 8. |
- Nilsson, Christer, et al.
(författare)
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Distribution of peptidergic nerves in the choroid plexus, focusing on coexistence of neuropeptide Y, vasoactive intestinal polypeptide and peptide histidine isoleucine
- 1990
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Ingår i: Regulatory Peptides. - : Elsevier BV. - 1873-1686 .- 0167-0115. ; 27:1, s. 11-26
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Tidskriftsartikel (refereegranskat)abstract
- Choroid plexus from rat, guinea-pig, rabbit and pig was investigated by light-microscopic immunohistochemistry and by radioimmunoassay for the presence of neuropeptides. A moderately dense supply of nerve fibers containing neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP), respectively, was found around blood vessels and in close relation to the secretory epithelium in both pig and rabbit, while lower densities of nerve fibers were found in rat and guinea-pig. Peptide concentrations ranged from 10-40 pmolequivalents/g (pmoleqv/g) for NPY and 0.5-6 pmoleqv/g for VIP in all four species. Peptide histidine isoleucine (PHI) immunoreactive nerve fibers were present in pig choroid plexus at a lower density than NPY and VIP but with a similar distribution. Low concentrations of substance P (0.3-3 pmoleqv/g) and calcitonin gene-related peptide (0.1-3 pmoleqv/g) were found to a varying degree in choroid plexus tissue from the different species, while immunohistochemical investigation was unable to detect any immunoreactive nerve fibers. NPY was often found to coexist with VIP and PHI in pig choroid plexus, while a lesser amount of nerve fibers showed coexistence of NPY and the noradrenaline synthetizing enzyme, dopamine-beta-hydroxylase. Surgical sympathetic denervation by excision of the superior cervical ganglion in the rabbit abolished NPY-containing nerve fibers, as revealed by immunohistochemistry, but only decreased NPY levels by one third, which may be due to different identity of the peptide being detected by the two techniques. It is concluded that NPY-containing nerve fibers have a dual origin in the choroid plexus and coexist with either noradrenaline or VIP/PHI.
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| 9. |
- Nilsson, Isabelle, 1971-, et al.
(författare)
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Pharmacological analysis of CCK2 receptor ligands using COS-7 and SK-N-MC cells, expressing the human CCK2 receptor
- 2002
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Ingår i: Regulatory Peptides. - 1873-1686 .- 0167-0115. ; 103:1, s. 29-37
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Tidskriftsartikel (refereegranskat)abstract
- A series of CCK2 receptor ligands were analysed with respect to their interaction with binding sites in the membranes of COS-7 cells and SK-N-MC cells transiently expressing the human CCK2 receptor (short isoform). The ligands were YF476, YM022, AG041R, L-740,093, JB93182, PD134308, and PD136450. Their binding was analysed by radioligand competition using [H-3]L-365,260 as the labelled ligand. Saturation binding analysis indicated that [H-3]L-365,260 interacted with a single class of binding sites. In competition binding experiments using COS-7-cell membranes, all seven ligands were incubated together with 2 nM [H-3]L-365,260. The data for four of the compounds fitted a one-site model (pK(i) values: YM022: 9.2 +/- 0.02, YF476: 9.6 +/- 0.04; L-740,093: 9.2 +/- 0.01, and AG041R: 8.3 +/- 0.06), while the data for the three others fitted a two-site model (pK(i) values: JB93182: 8.8 +/- 0.04 and 6.0 +/- 0.15; PD 134308: 9.0 +/- 0.04 and 6.1 +/- 0.15; and PD 136450: 9.0 +/- 0.02 and 5.4 +/- 0.41). SK-N-MC cell membranes and 2 nM [H-3]L-365,260 were incubated together with YM022, YF476, JB93182, and PD134308. The data for YM022 and YF476 fitted a one-site model (pKi values: YM022: 9.3 +/- 0.06, YF476: 9.4 +/- 0.02), while the data for JB93182 and PD134308 fitted a two-site model (pK(i) values: JB93182: 8.7 +/- 0.06 and 6.2 +/- 0.06; PD134308: 9.1 +/- 0.06 and 7.0 +/- 0.17). Competition binding experiments in the presence of the GTP-analogue guanylylimidodiphosphate, using either of the two cell types, produced similar binding data for PD 134308 and JB93182 as in the absence of GTP-analogue. The human receptor seems to exist in a low and/or high affinity state. The shift from low to high affinity does not seem to reflect the degree of G protein coupling.
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| 10. |
- Portela-Gomes, GM, et al.
(författare)
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PACAP is expressed in secretory granules of insulin and glucagon cells in human and rodent pancreas - Evidence for generation of cAMP compartments uncoupled from hormone release in diabetic islets
- 2003
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Ingår i: Regulatory Peptides. - 1873-1686 .- 0167-0115. ; 113, s. 31-
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Tidskriftsartikel (refereegranskat)abstract
- Pituitary adenylate cyclase-activating polypeptide (PACAP) is an islet neuropeptide with potent insulinotropic action. The current study investigates PACAP expression in normal human and rat pancreatic islets, and whether it is altered in diabetic state. To that end, PACAP immunoreactivity was studied by immunofluorescence methods enhanced by the catalyzed reporter deposition (CARD) technique. Insulin and cyclic adenosine monophosphate (cAMP) generation induced by PACAP were investigated in islets isolated from the spontaneously diabetic Goto-Kakizaki (GK) rat. PACAP immunoreactivity was observed in virtually all insulin and glucagon cells in both species, but not in somatostatin or pancreatic polypeptide (PP) cells; this co-localization pattern was unaltered in diabetic pancreata. In normal human pancreas, PACAP was further localized ultrastructurally to the secretory granules of insulin and glucagon cells. PACAP significantly potentiated glucose-stimulated insulin release in isolated islets of normal but not of GK rats. PACAP failed to enhance cAMP generation in normal islets, but induced similar to 5-folds exaggeration in the diabetic islets. In conclusion, using improved immunocytochemistry techniques and electron microscopy (EM), PACAP was shown to be expressed both in normal and diabetic islet cells and localized to secretory granules of insulin and glucagon cells. Furthermore, the insulinotropic action of PACAP was markedly impaired in diabetic islets in spite of exaggerated cAMP response. (C) 2003 Elsevier Science B.V. All rights reserved.
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| 11. |
- Sharma, P, et al.
(författare)
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Cloning and functional expression of the guinea pig neuropeptide Y Y2 receptor
- 1998
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Ingår i: Regulatory Peptides. - : Elsevier BV. - 0167-0115. ; 75-76, s. 23-28
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Tidskriftsartikel (refereegranskat)abstract
- Five neuropeptide Y (NPY) receptor subtypes have been cloned in mammals. The degree of sequence conservation differs considerably between subtypes as well as between evolutionary lineages. To shed further light on this, we have cloned the five NPY receptors in the guinea pig. Here, we report the cloning of the guinea pig Y2 receptor. The Y2 receptor is generally highly conserved, with 90-95% identity between different orders of mammals, including the guinea pig. The guinea pig receptor has a divergent cytoplasmic tail, indicating possible differences in regulation of signalling and/or down regulation. COS-7 cells transiently transfected with the gpY2 receptor show saturable 125I-PYY binding with a Kd = 6 pM. In displacement experiments, the gpY2 receptor was similar to the human and rat receptors with the following rank order of potencies: pNPY > pPYY > pNPY13-36 = pNPY22-36 > [Leu31Pro34]NPY > BIBP3226. Thus, the guinea pig Y2 receptor is well conserved in comparison with human and rat with regard to both amino acid sequence and pharmacological profile.
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| 12. |
- Stjernquist, Martin, et al.
(författare)
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Immunocytochemical localization of galanin in the rat male and female genital tracts and motor effects in vitro
- 1988
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Ingår i: Regulatory Peptides. - : Elsevier BV. - 1873-1686 .- 0167-0115. ; 20:4, s. 335-343
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Tidskriftsartikel (refereegranskat)abstract
- Galanin, a recently discovered neuropeptide, was studied in the rat male and female reproductive tracts by immunocytochemistry and in vitro pharmacology. Nerve fibers containing galanin immunoreactivity were most abundant in the female paracervical tissue, where they surrounded non-immunoreactive ganglion cells. Galanin nerves were also found in the uterus and Fallopian tubes, as well as in the vas deferens. When tested in vitro galanin contracted the smooth muscle of both the uterine horn and cervix. Galanin also slightly potentiated the response to electrical field stimulation in preparations from the uterine cervix and vas deferens, but it had no effect on the seminal vesicle. Galanin-(1-10), an N-terminal residue of galanin, also contracted the uterine horn, though higher concentrations were required. The neurally induced contractions were not influenced by galanin-(1-10) in any of the smooth muscle preparations tested. The muscle receptors mediating the direct contractile effects in the uterine horn seem to require the N-terminus of galanin, while the neuromodulatory effects on the electrically induced contractile activity seem to need the C-terminal part or the whole galanin molecule. Galanin may thus function as a neuromediator in the rat male and female genital organs.
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| 25. |
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| 26. |
- El-Salhy, M, et al.
(författare)
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Neuroendocrine peptide levels in the gastrointestinal tract of mice after unilateral cervical vagotomy
- 2000
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Ingår i: Regulatory Peptides. - 0167-0115 .- 1873-1686. ; 88:1-3, s. 15-20
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Tidskriftsartikel (refereegranskat)abstract
- The effects of left and right unilateral cervical vagotomy on the content of several neuroendocrine peptides were studied in different parts of the murine gastrointestinal tract, known to receive vagal innervation. The neuroendocrine peptides investigated were secretin, gastric inhibitory peptide (GIP), gastrin, motilin, peptide YY (PYY), somatostatin, substance P, VIP, neurotensin, neuropeptide Y (NPY), and galanin. The neuroendocrine peptide concentration was affected after both left and right vagotomy, and that the changes in the concentrations of the neuroendocrine peptide levels occurred in all the gastrointestinal segments investigated, namely antrum, small and large intestine. However, these changes varied, depending on which side was vagotomized and the interval after vagotomy. It is concluded that the vagus nerve had an important impact on the neuroendocrine system in the murine gut. It is suggested, furthermore that the contradictory results obtained earlier on the effect of vagotomy on the gastrointestinal peptides may depend on differences in the vagotomy methods used and on differences in observation time after vagotomy.
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| 27. |
- El-Salhy, Magdy, et al.
(författare)
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Triple therapy with octreotide, galanin and serotonin induces necrosis and increases apoptosis of a rat colon carcinoma
- 2002
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Ingår i: Regulatory Peptides. - : Elsevier. - 0167-0115 .- 1873-1686. ; 108:2-3, s. 55-62
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Tidskriftsartikel (refereegranskat)abstract
- A rat colonic adenocarcinoma was implanted subcutaneously (s.c.) in nude mice. After 7 days, the animals were divided into different groups. Two groups received subcutaneous injections twice daily with 3 or 6 μg/kg body weight octreotide, galanin and serotonin. Three groups were respectively treated with 20, 30, and 40 μg/kg body weight of the previously mentioned bioactive substances. Control group received only saline solution in the same fashion as treated animals. The treatment lasted for 5 days. The tumour volume and weight, the relative density of blood vessels, of tumour necrotic tissue, of apoptotic nuclei and of proliferating nuclei were measured. Apoptosis was detected by in situ labelling of nuclear DNA fragmentation according to TUNEL method, and proliferation by immunocytochemistry. Morphometry was done with the classical stereological point-counting method. Food consumption, animal weight, faeces weight and its water content were measured for 3 days before and after treatment. Triple therapy with 3 and 6 μg/kg body weight had no effect on any of the parameters measured, except in reducing the relative volume density of tumour blood vessels. Treatment with 20, 30 and 40 μg/kg body weight of the previously mentioned bioactive substances reduced the tumour volume, the relative volume density of blood vessels and increased the relative volume density of necrotic tissue and of apoptotic nuclei (in the 20 μg group). However, there was no difference between treated mice and controls regarding the relative volume density of proliferating nuclei. There was no statistical difference between treated animals regarding food consumption, body weight, faeces weight and its water content before and during treatment. The present study confirms that triple therapy with octreotide, galanin and serotonin causes regression of a rat colon carcinoma. It further showed that optimum treatment dose is 20 μg/kg body weight of each bioactive substance. Moreover, this therapy regime does not show apparent side effects in the experiments carried out on mice.
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| 28. |
- El-Salhy, Magdy, et al.
(författare)
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Triple therapy with octreotide, galanin, and serotonin reduces the size and blood vessel density and increases apoptosis of a rat colon carcinoma
- 2003
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Ingår i: Regulatory Peptides. - : Elsevier. - 0167-0115 .- 1873-1686. ; 111:1-3, s. 145-152
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Tidskriftsartikel (refereegranskat)abstract
- A rat colonic adenocarcinoma was implanted subcutaneously in female nude (C57BL/6JBom-nu) mice. After 7 days, the animals were divided into different groups. One group received triple therapy with octreotide, galanin, and serotonin, 10 μg/kg body weight of each, twice daily. The second group served as controls and received only saline solution. Three groups received 10 μg/kg body weight twice daily of octreotide, galanin, or serotonin. The last group consisted of controls that received only saline solution. The treatment lasted for 5 days. The tumour volume, wet weight, and relative volume density of blood vessels were significantly decreased after the triple treatment, as compared to controls. Apoptotic index was significantly increased, but the proliferation index was not affected in the group of mice that received triple therapy. There was no significant difference between controls and mice treated with octreotide, galanin, or serotonin regarding tumour volume or weight. The relative volume density of blood vessels was decreased in tumours treated with galanin, but not with octreotide or serotonin. There was no statistical difference in the proliferation index between controls and animals treated with octreotide, galanin, or serotonin, as compared with controls. Tumour necrosis and increased apoptosis may be responsible for the reduction in the volume and weight of the tumour after triple therapy. Tumour necrosis may be caused by the induction of tumour ischemia due to a reduction in tumour blood flow, which is caused by decreased incidence of tumour-feeding blood vessels, and by constriction of tumour-feeding arterioles. These results are promising and may offer treatment for colon cancer.
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| 29. |
- Ericson, Ann-Charlott, 1965-, et al.
(författare)
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Morphological examination of the termination pattern of substance P-immunoreactive nerve fibers in human antral mucosa
- 2002
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Ingår i: Regulatory Peptides. - 0167-0115 .- 1873-1686. ; 107:1-3, s. 79-86
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Tidskriftsartikel (refereegranskat)abstract
- The termination pattern of substance P (SP)-containing axons in human antral mucosa was examined using immunohistochemical techniques at the light and electron microscopic level. SP-immunoreactive (IR) axons were found to extend towards the pit region of the glands, where intraepithelial axons were observed. Electron microscopy showed immunostained axon profiles in close contact with the basement membrane of surface mucous cells. Membrane-to-membrane contacts between labeled axons and myofibroblast-like cells were identified, and SP-IR axons that were apposed to the epithelium were also in contact with subjacent myofibroblast-like cells. The anatomical relationship between SP-IR axons and the cells of the muscularis mucosae was investigated by light microscopy. Immunoreactivity for a-smooth muscle actin (a-sma) was used to visualize the smooth muscle cells, and the a-sma-IR cells were found to create a network that surrounded the gastric glands. Immunostained varicose axons ran alongside and in close apposition to the labeled muscle strands. Ultrastructural examination showed close contacts between SP-IR axon profiles and smooth muscle-like cells. In conclusion, SP-containing neurons may be important for sensory and secretomotor functions in the human antral mucosa.
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| 30. |
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| 31. |
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| 32. |
- Gunnarsson, Tove, et al.
(författare)
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Cholecystokinin peptides in cerebrospinal fluid : a study in healthy male subjects
- 1997
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Ingår i: Regulatory Peptides. - 0167-0115 .- 1873-1686. ; 68:1, s. 57-61
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Tidskriftsartikel (refereegranskat)abstract
- The clinical reliability of measuring cholecystokinin (CCK) peptides in the cerebrospinal fluid (CSF) has not been fully elucidated. Therefore, we have assayed CCK-8S and CCK-4 in CSF obtained from 14 healthy male subjects, lumbar-punctured at the L4–5 level following a strictly standardised procedure. CSF concentrations of free CCK-8S and free CCK-4 were used as dependent variables while age, height, body weight, atmospheric pressure and some other factors served as independent variables. It was shown that the CCK-8S ratio between the second (7–12 ml) and first (0–6 ml) CSF fractions, correlated significantly with the atmospheric pressure at the time of puncture. Neither CCK-8S nor CCK-4 displayed concentration gradients in CSF. The CCK-4 levels, expressed as pmol l−1 in the total amount of CSF were found to be positively correlated with the neuraxis distance in the lying position and negatively with the neuraxis distance in the sitting position. Furthermore, CCK-4, expressed as pmol l−1 per min of tapping-time (pmol l−1 min−1), showed a negative correlation with storage time, presumably mirroring a proteolytic process. CCK-8S and CCK-4 intercorrelated positively independently of whether expressed as pmol l−1 or pmol l−1 min−1. In conclusion, the results of this exploratory study indicate that the neuraxis distance (in the sitting and lying positions) and storage-time have to be accounted for when interpreting data on CSF levels of CCK-4. Attention has to be paid to the potential influence of atmospheric pressure on the concentration ratio of CCK-8S.
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| 46. |
- Nilsson, Isabelle, 1971-, et al.
(författare)
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Molecular cloning of an unusual bicistronic cholecystokinin receptor mRNA expressed in chicken brain : a structural and functional expression study
- 2003
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Ingår i: Regulatory Peptides. - 0167-0115 .- 1873-1686. ; 114:1, s. 37-43
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Tidskriftsartikel (refereegranskat)abstract
- This report describes the molecular cloning and pharmacological characterization of a transiently expressed chicken brain cholecystokinin receptor (CCK-CHR) in COS-7 cells. A polymerase chain reaction (PCR)-based cloning strategy was applied using: (1) an initial PCR with deoxyinosine-containing primers designed to target conserved regions in CCK receptors, followed by (2) rapid amplification of cDNA ends (RACE), and (3) full-length PCR of the CCK-CHR cDNA. The full-length cloned bicistronic CCK-CHR cDNA contained a short upstream open reading frame (uORF) coding for a putative six-amino-acid-long peptide of unknown function, followed by a long open reading frame (lORF) encoding the 436-amino-acid-long CCK-CHR receptor protein. At the amino acid level, the CCK-CHR shared ∼50% homology with mammalian and Xenopus laevis CCK receptors. The pharmacological profile of CCK-CHR resembled that of CCK-B receptors using agonists (CCK-8, CCK-4, gastrin-17), whereas CCK-CHR showed higher affinity for the CCK-A receptor antagonist, devazepide, than for the CCK-B receptor antagonist, l-365,260. To the best of our knowledge, this is the first description and functional expression study of a cloned chicken CCK receptor cDNA.
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| 47. |
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| 48. |
- Nässel, Dick, et al.
(författare)
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Evidence that locustatachykinin I is involved in release of adipokinetic hormone from locust corpora cardiaca
- 1995
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Ingår i: Regulatory Peptides. - 0167-0115 .- 1873-1686. ; 57:3, s. 297-310
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Tidskriftsartikel (refereegranskat)abstract
- The glandular cells of the corpus cardiacum of the locust Locusta migratoria, known to synthesize and release adipokinetic hormones (AKH), are contacted by axons immunoreactive to an antiserum raised against the locust neuropeptide locustatachykinin I (LomTK I). Electron-microscopical immunocytochemistry reveals LomTK immunoreactive axon terminals, containing granular vesicles, in close contact with the glandular cells cells. Release of AKH I from isolated corpora cardiaca of the locust has been monitored in an in vitro system where the amount of AKH I released into the incubation saline is determined by reversed phase high performance liquid chromatography with fluorometric detection. We could show that LomTK I induces release of AKH from corpora cardiaca in a dose-dependent manner when tested in a range of 10-200 microM. This is thus the first clear demonstration of a substance inducing release of AKH, correlated with the presence of the substance in fibers innervating the AKH-synthesizing glandular cells, in the insect corpora cardiaca.
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| 49. |
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| 50. |
- Portela-Gomes, Guida M., et al.
(författare)
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Co-localization of chromogranins and neuroendocrine hormones in the human gastrointestinal mucosa
- 1996
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Ingår i: Regulatory Peptides. - : Elsevier BV. - 0167-0115 .- 1873-1686. ; 64:1, s. 154-154
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Recension (refereegranskat)abstract
- Co-localization of chromogranin (Cg) A, B and C has been studied in different neuroendocrine cell types in histologically normal mucosa from human gastrointestinal (GI) tract (corpus, antrum, duodenum, ileum and colon). Single, double and triple immunofluorescence stains were used, including appropriate controls. The results showed that whereas CgA cells predominated in all GI-regions, CgB cells were numerous in antrum, few in duodenum (only villi), and almost non-existent in corpus, ileum and colon. CgC cells were sparse in antrum and duodenum (only crypts). Concerning co-localization, gastrin cells harboured CgA and B, some also CgC. All EC cells displayed CgA-immunoreactivity. The EC cells localized in the luminal 23 of the antral mucosa and those in the duodenal villi also contained CgB. Occasionally the EC cells in the duodenal crypts displayed CgC. Almost all cells showing immunoreaction to enteroglucagon/PYY, secretin, neurotensin, or GIP were positive for CgA. Somatostatin cells were with few exceptions CgA-negative, and displayed neither CgB nor C immunoreactivity. CCK cells, indirectly identified, were negative for CgB and C, probably also for CgA.Regarding intracellular localization, CgA and C were seen closer to the basal cell regions, whereas CgB was found more diffusely spread throughout the cytoplasm. This difference in localization between chromogranins suggests that not all secretory granules contain CgA or that CgB may appear in a non-granular form. The results confirm previous findings that CgA occurs in most neuroendocrine cell types of the GI-tract. In most gastrin cells there were two sets of chromogranins, CgA and B, a minority all three chromogranins. All EC cells were CgA immunoreactive, a minority also contained CgB (antrum + duodenal villi) or CgC (duodenal crypts), but not both. All CCK cells seem to be devoid of chromogranins. With few exceptions the same was true of the somatostatin cells. An interesting question posed by the present study is why the chromogranins occur in varying extent and composition in the different cell types.
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