| 1. |
- Bungart, D, et al.
(författare)
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Occurrence of analogues of the myotropic neuropeptide orcokinin in the shore crab, Carcinus maenas : evidence for a novel neuropeptide family.
- 1995
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Ingår i: Peptides. - 0196-9781 .- 1873-5169. ; 16:1, s. 67-72
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Tidskriftsartikel (refereegranskat)abstract
- By use of an enzyme immunoassay that was developed for the determination of orcokinin, a myotropic neuropeptide of the sequence NFDEIDRSGFGFN from the crayfish, Orconectes limosus, immunoreactive material was detected in extracts of thoracic ganglia from the shore crab, Carcinus maenas. Isolation of the immunoreactive material was achieved by the following steps: 1) prepurification by gel filtration, 2) immunoaffinity chromatography on an anti-orcokinin IgG protein-A sepharose column, and 3) reversed-phase HPLC. The HPLC profile after affinity purification revealed three main immunoreactive peptides that were rechromatographed. None of these peptides was identical to orcokinin in terms of retention time. Automated gas-phase sequencing revealed these peptides to be analogues of orcokinin differing in one amino acid residue. They were named [Ser9]-, [Ala13]- and [Val13]orcokinin (NFDEIDRSSFGFN, Mr 1549.3; NFDEIDRSGFGFA, Mr 1475.3; NFDEIDRSGFGFV, Mr 1503.9). Carboxypeptidase A treatment of the peptides indicated a free C-terminus. Complete characterization of the three peptides was achieved from approximately 230 thoracic ganglia of Carcinus maenas.
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| 2. |
- Bungart, D, et al.
(författare)
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Quantitative determination and distribution of the myotropic neuropeptide orcokinin in the nervous system of astacidean crustaceans.
- 1994
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Ingår i: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 15:3, s. 393-400
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Tidskriftsartikel (refereegranskat)abstract
- For quantitative determinations of orcokinin, an indirect, noncompetitive sandwich ELISA was developed. This ELISA is highly specific for orcokinin and the detection limit is 1 fmol. In three astacidean species (Orconectes limosus, Homarus americanus, and Astacus astacus) orcokinin immunoreactivity (OK-IR) was measurable in all parts of the nervous system. Upon normalization to the protein content of the tissue (pmol/mg protein), concentrations were shown to be in the same range in all three species. The distribution of OK-IR in the nervous system is also very similar in the three species. In Orconectes limosus the following values were obtained (in pmol/mg protein): cerebral ganglion 215, optic ganglia in the eyestalk 38, subesophageal ganglion 182. The thoracic ganglia have lower concentrations (35-72) and the abdominal ganglia (AG) 1-5 even lower ones (11-17). In the AG 6 of Orconectes, from which the innervation of the hindgut arises, concentrations are approximately five times higher than in the other AG. In hindgut tissue, relatively high concentrations of 22 pmol/mg were measured, which is in agreement with the demonstrated function of orcokinin as a hindgut excitatory substance. Markedly elevated levels of orcokinin were observed in the AG 6 of Astacus, but not in Homarus. Orcokinin could also be measured consistently and reliably in the hemolymph, where its concentration is approximately 1 x 10(-11) M. These results show that orcokinin may be released into the hemolymph and may act as a hormone, in addition to its role as a locally acting neurotransmitter/modulator.
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| 3. |
- Dircksen, Heinrich, 1954-, et al.
(författare)
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Structure, distribution, and biological activity of novel members of the allatostatin family in the crayfish Orconectes limosus.
- 1999
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Ingår i: Peptides. - 0196-9781 .- 1873-5169. ; 20:6, s. 695-712
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Tidskriftsartikel (refereegranskat)abstract
- In the central and peripheral nervous system of the crayfish, Orconectes limosus, neuropeptides immunoreactive to an antiserum against allatostatin I (= Dipstatin 7) of the cockroach Diploptera punctata have been detected by immunocytochemistry and a sensitive enzyme immunoassay. Abundant immunoreactivity occurs throughout the central nervous system in distinct interneurons and neurosecretory cells. The latter have terminals in well-known neurohemal organs, such as the sinus gland, the pericardial organs, and the perineural sheath of the ventral nerve cord. Nervous tissue extracts were separated by reverse-phase high-performance liquid chromatography and fractions were monitored in the enzyme immunoassay. Three of several immunopositive fractions have been purified and identified by mass spectroscopy and microsequencing as AGPYAFGL-NH2, SAGPYAFGL-NH2, and PRVYGFGL-NH2. The first peptide is identical to carcinustatin 8 previously identified in the crab Carcinus maenas. The others are novel and are designated orcostatin I and orcostatin II, respectively. All three peptides exert dramatic inhibitory effects on contractions of the crayfish hindgut. Carcinustatin 8 also inhibits induced contractions of the cockroach hindgut. Furthermore, this peptide reduces the cycle frequency of the pyloric rhythms generated by the stomatogastric nervous system of two decapod species in vitro. These crayfish allatostatin-like peptides are the first native crustacean peptides with demonstrated inhibitory actions on hindgut muscles and the pyloric rhythm of the stomatogastric ganglion.
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| 4. |
- Stangier, Joachim, et al.
(författare)
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Distribution of a novel cardioactive neuropeptide (CCAP) in the nervous system of the shore crab Carcinus maenas
- 1988
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Ingår i: Peptides. - : Elsevier. - 0196-9781 .- 1873-5169. ; 9:4, s. 795-800
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Tidskriftsartikel (refereegranskat)abstract
- A radioimmunoassay (RIA) for the recently discovered crustacean cardioactive peptide (CCAP) has been developed and used to determine contents of CCAP in different parts of the nervous system of the shore crab Carcinus maenas. Immunoreactive material was detected throughout the nervous system. In contrast to the main ganglia which contained low levels of approximately 1.4 pmol CCAP/mg protein (brain and thoracic ganglion), a high concentration was found in a neurohemal structure, the pericardial organs (PO) (868 pmol/mg protein). A predominantly neurohormonal role of CCAP thus suggested is further supported by in vitro release studies. Incubation of POs in high (K+) saline showed that CCAP is secretable in considerable amounts by a Ca++-dependent release mechanism.
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| 5. |
- Stangier, J, et al.
(författare)
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Identification and immunocytochemical localization of proctolin in pericardial organs of the shore crab, Carcinus maenas.
- 1986
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Ingår i: Peptides. - : Elsevier. - 0196-9781 .- 1873-5169. ; 7:1, s. 67-72
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Tidskriftsartikel (refereegranskat)abstract
- The occurrence of proctolin (Arg-Tyr-Leu-Pro-Thr) in crab neurohemal pericardial organs (POs) has been demonstrated by isolation of the pentapeptide by HPLC and manual microsequencing according to the DABITC-PITC double coupling technique. From one pair of POs approximately 5.4 pmol were obtained (= 45 pmol/mg protein). Immunocytochemically, an extensive system of positive structures was found in both whole mount preparations and semithin sections, consisting of numerous varicose fibres of varying diameter and many knoblike neurosecretory terminals abutting upon the epineurium of the PO trunks. The relatively high concentration in the POs as well as the pattern of proctolin-positive fibres and terminals clearly suggest a neurohormonal role of the pentapeptide in decapod crustaceans.
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| 6. |
- Blackshear, Alice, et al.
(författare)
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Intracerebroventricular administration of galanin or galanin receptor subtype 1 agonist M617 induces c-Fos activation in central amygdala and dorsomedial hypothalamus
- 2007
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Ingår i: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 28:5, s. 1120-1124
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Tidskriftsartikel (refereegranskat)abstract
- The neuropeptide galanin and galanin receptors are widespread throughout cortical, limbic and midbrain areas implicated in reward, learning/memory, pain, drinking and feeding. While many studies have shown that galanin produces a variety of presynaptic and postsynaptic responses, work studying the effects of galanin on neural activation is limited. The present study examined patterns of c-Fos immunoreactivity resulting from intracerebro-ventricular administration of galanin versus saline injection in awake rats. An initial comprehensive qualitative survey was conducted to identify regions of high c-Fos expression followed up with quantitative analysis. Galanin induced a significant increase in c-Fos levels relative to saline-treated controls in dorsomedial hypothalamus and in the central nucleus of the amygdala. This pattern of activation was also produced by galanin receptor type 1 agonist M617. The present findings confirm that galanin upregulates c-Fos activation in hypothalamic nuclei, and supports roles for galanin in central amygdala-mediated food intake, and Pavlovian conditioning.
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| 7. |
- Melas, Philippe A., et al.
(författare)
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Neuropeptide Y : Identification of a novel rat mRNA splice-variant that is downregulated in the hippocampus and the prefrontal cortex of a depression-like model
- 2012
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Ingår i: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 35:1, s. 49-55
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Tidskriftsartikel (refereegranskat)abstract
- Neuropeptide Y (NPY) is known to influence emotional processing and decreased NPY levels have been associated with mood and anxiety disorders. Alternative splicing of pre-messenger RNA is a cellular mechanism that allows for transcriptome diversity, yet there is limited knowledge in this respect with regard to Npy. Since the hippocampus and the prefrontal cortex play an important role in affective disorders, we investigated alternative splicing of Npy in these regions of a rat model of depression (Flinders Sensitive Line, FSL) and its controls (Flinders Resistant Line, FRL). The existence of different Npy messenger RNA (mRNA) variants was examined using 5' and 3' RACE. In addition to the Npy mRNA species annotated in GenBank and Ensembl, we identified a novel short mRNA splice variant. Immunoblotting results argued against a putative translation of this short mRNA into protein in brain tissue. Compared to the FRL, the FSL had reduced short Npy mRNA levels in the HIP (P = 0.00014) and the PFC (P = 0.016). Gene expression analyses in five brain regions of an outbred rat strain supported the presence of the short Npy transcript in all examined regions and showed that it is expressed in similar to 2.4-fold lower levels than the long Npy mRNA. Finally, sequencing of the 5' RACE products revealed a transcription start site of Npy that is different from the currently annotated position. These data add to the characterization of the rat Npy mRNA and demonstrate the presence of a novel transcript with a so far unknown function.
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| 8. |
- Nachman, Ronald J., et al.
(författare)
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Biostable multi-Aib analogs of tachykinin-related peptides demonstrate potent oral aphicidal activity in the pea aphid Acyrthosiphon pisum (Hemiptera : Aphidae)
- 2011
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Ingår i: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 32:3, s. 587-594
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Tidskriftsartikel (refereegranskat)abstract
- The tachykinin-related peptides (TRPs) are multifunctional neuropeptides found in a variety of arthropod species, including the pea aphid Acyrthosiphon pisum (Hemiptera: Aphidae). Two new biostable TRP analogs containing multiple, sterically hindered Aib residues were synthesized and found to exhibit significantly enhanced resistance to hydrolysis by angiotensin converting enzyme and neprilysin, membrane-bound enzymes that degrade and inactivate natural TRPs. The two biostable analogs were also found to retain significant myostimulatory activity in an isolated cockroach hindgut preparation, the bioassay used to isolate and identify the first members of the TRP family. Indeed one of the analogs (Leuma-TRP-Aib-1) matched the potency and efficacy of the natural, parent TRP peptide in this myotropic bioassay. The two biostable TRP analogs were further fed in solutions of artificial diet to the pea aphid over a period of 3 days and evaluated for antifeedant and aphicidal activity and compared with the effect of treatment with three natural, unmodified TRPs. The two biostable multi-Aib TRP analogs were observed to elicit aphicidal effects within the first 24h. In contrast natural, unmodified TRPs, including two that are native to the pea aphid, demonstrated little or no activity. The most active analog, double-Aib analog Leuma-TRP-Aib-1 (pEA[Aib]SGFL[Aib]VR-NH(2)), featured aphicidal activity calculated at an LC(50) of 0.0083nmol/μl (0.0087μg/μl) and an LT(50) of 1.4 days, matching or exceeding the potency of commercially available aphicides. The mechanism of this activity has yet to be established. The aphicidal activity of the biostable TRP analogs may result from disruption of digestive processes by interfering with gut motility patterns and/or with fluid cycling in the gut; processes shown to be regulated by the TRPs in other insects. These active TRP analogs and/or second generation analogs offer potential as environmentally friendly pest aphid control agents.
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| 9. |
- Nässel, Dick R., et al.
(författare)
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A comparative review of short and long neuropeptide F signaling in invertebrates : Any similarities to vertebrate neuropeptide Y signaling?
- 2011
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Ingår i: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 32:6, s. 1335-1355
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Forskningsöversikt (refereegranskat)abstract
- Neuropeptides referred to as neuropeptide F (NPF) and short neuropeptide F (sNPF) have been identified in numerous invertebrate species. Sequence information has expanded tremendously due to recent genome sequencing and EST projects. Analysis of sequences of the peptides and prepropeptides strongly suggest that NPFs and sNPFs are not closely related. However, the NPFs are likely to be ancestrally related to the vertebrate family of neuropeptide Y (NPY) peptides. Peptide diversification may have been accomplished by different mechanisms in NPFs and sNPFs; in the former by gene duplications followed by diversification and in the sNPFs by internal duplications resulting in paracopies of peptides. We discuss the distribution and functions of NPFs and their receptors in several model invertebrates. Signaling with sNPF, however, has been investigated mainly in insects, especially in Drosophila. Both in invertebrates and in mammals NPF/NPY play roles in feeding, metabolism, reproduction and stress responses. Several other NPF functions have been studied in Drosophila that may be shared with mammals. In Drosophila sNPFs are widely distributed in numerous neurons of the CNS and some gut endocrines and their functions may be truly pleiotropic. Peptide distribution and experiments suggest roles of sNPF in feeding and growth, stress responses, modulation of locomotion and olfactory inputs, hormone release, as well as learning and memory. Available data indicate that NPF and sNPF signaling systems are distinct and not likely to play redundant roles.
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| 10. |
- Palm, Caroline, et al.
(författare)
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Quantitatively determined uptake of cell-penetrating peptides in non-mammalian cells with an evaluation of degradation and antimicrobial effects
- 2006
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Ingår i: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 27:7, s. 1710-1716
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Tidskriftsartikel (refereegranskat)abstract
- Cell-penetrating peptides (CPPs) are carriers developed to improve mammalian cell uptake of important research tools such as antisense oligonucleotides and short interfering RNAs. However, the data on CPP uptake into non-mammalian cells are limited. We have studied the uptake and antimicrobial effects of the three representative peptides penetratin (derived from a non-mammalian protein), MAP (artificial peptide) and pVEC (derived from a mammalian protein) using fluorescence HPLC in four common model systems: insect cells (Sfg), gram-positive bacteria (Bacillus megaterium), gram-negative bacteria (Escherichia coli) and yeast (Saccharomyces cerevisiae). We demonstrate that non-mammalian cells internalize CPPs and a comparison of the uptake of the peptides show that the intracellular concentration and degradation of the peptides varies widely among organisms. In addition, these CPPs showed antimicrobial activity.
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