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- Ekblad, Eva, et al.
(författare)
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Cocaine- and amphetamine-regulated transcript: distribution and function in rat gastrointestinal tract.
- 2003
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Ingår i: Neurogastroenterology and Motility. - : Wiley. - 1350-1925 .- 1365-2982. ; 15:5, s. 545-557
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Tidskriftsartikel (refereegranskat)abstract
- Cocaine- and amphetamine-regulated transcript (CART) peptide, originally isolated from brain, is also expressed in the peripheral nervous system. The distribution, origin and projections of CART-expressing enteric neurones by immunocytochemistry and in situ hybridization in rat gastrointestinal (GI) tract were studied. Possible motor functions of CART were studied in vitro using longitudinal muscle strips from stomach, ileum and colon. Cocaine- and amphetamine-regulated transcript peptide was found in numerous myenteric neurones throughout the GI tract while CART-expressing submucous neurones were scarce. Cocaine- and amphetamine-regulated transcript was also expressed in the antral gastrin cells. Myenteric CART-expressing neurones in both small and large intestine issued short descending projections. In atrophic ileum, CART mRNA-expressing neurones increased in number while neurones containing CART peptide decreased. In hypertrophied ileum, no change in CART peptide or CART mRNA containing myenteric neurones was detected. Cocaine- and amphetamine-regulated transcript 55-102 (10-9-10-7 mol L-1) did not induce any contractile or relaxatory responses in the muscle strips, neither did it affect responses induced by vasoactive intestinal peptide, pituitary adenylate cyclase-activating peptide or neuronal stimulation. In colonic, but not in ileal, strips addition of CART attenuated nitric oxide (NO) donor-induced relaxations. Although CART does not seem to play a pivotal role in classic neurotransmission to the longitudinal muscle, it may serve a modulatory role in NO transmission. It may, moreover, be involved in intestinal adaptation, and an additional hormonal role is also possible.
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| 2. |
- Husebye, Einar, et al.
(författare)
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Influence of microbial species on small intestinal myoelectric activity and transit in germ-free rats
- 2001
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Ingår i: American Journal of Physiology: Gastrointestinal and Liver Physiology. - 1522-1547. ; 280:3, s. 368-380
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Tidskriftsartikel (refereegranskat)abstract
- The effect of an intestinal microflora consisting of selected microbial species on myoelectric activity of small intestine was studied using germ-free rat models, with recording before and after specific intestinal colonization, in the unanesthetized state. Intestinal transit, neuropeptides in blood (RIA), and neuromessengers in the intestinal wall were determined. Clostridium tabificum vp 04 promoted regular spike burst activity, shown by a reduction of the migrating myoelectric complex (MMC) period from 30.5 +/- 3.9 min in the germ-free state to 21.2 +/- 0.14 min (P< 0.01). Lactobacillus acidophilus A10 and Bifidobacterium bifidum B11 reduced the MMC period from 27.9 +/- 4.5 to 21.5 +/- 2.1 min (P< 0.02) and accelerated small intestinal transit (P< 0.05). Micrococcus luteus showed an inhibitory effect, with an MMC period of 35.9 +/- 9.3 min compared with 27.7 +/- 6.3 min in germ-free rats (P< 0.01). Inhibition was indicated also for Escherichia coli X7 gnotobiotic rats. No consistent changes in slow wave frequency were observed. The concentration of neuropeptide Y in blood decreased after introduction of conventional intestinal microflora, suggesting reduced inhibitory control. Intestinal bacteria promote or suppress the initiation and aboral migration of the MMC depending on the species involved. Bacteria with primitive fermenting metabolism (anaerobes) emerge as important promoters of regular spike burst activity in small intestine.
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| 3. |
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| 4. |
- Jongsma, Helen, et al.
(författare)
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Alteration of PACAP distribution and PACAP receptor binding in the rat sensory nervous system following sciatic nerve transection
- 2000
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Ingår i: Brain Research. - 0006-8993. ; 853, s. 96-186
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Tidskriftsartikel (refereegranskat)abstract
- Pituitary adenylate cyclase activating polypeptide (PACAP) is a widely expressed neuropeptide that has been involved in nerve regeneration, neurone survival and nociception. In this study, the distribution of PACAP and PACAP-receptors were investigated in rat dorsal root ganglia (DRG), spinal cord and medulla oblongata at 3, 7 or 14 days following unilateral sciatic nerve transection using immunohistochemistry, 125I-PACAP-binding and in situ hybridisation. In control (contralateral side) DRG, about 30% of the nerve cell bodies (92% being small) were PACAP-immunoreactive (PACAP-IR). In the spinal cord, PACAP-IR fibres were seen in laminae I-II but not in the gracile nuclei. Following sciatic nerve transection, PACAP-IR fibres appeared in the gracile nuclei and occasionally in the deeper laminae of the dorsal horn consistent with the relative increase in larger PACAP-IR DRG neurones. However, the relative number of small PACAR-IR neurones was significantly lower on the transected side as compared to the control side suggesting a dual reaction for PACAP in the DRG following nerve injury. 125I-PACAP-binding was found in laminae I-II, around the central canal and in the gracile nuclei but not in the DRG. At 14 days after transection, 125I-PACAP-binding density was significantly reduced in the ipsilateral dorsal horn. PACAP-receptor (PAC(1)) mRNA was detected in neurones of the dorsal and ventral horn and in the gracile nuclei with no overt changes observed after transection. Very few DRG nerve cell bodies contained PAC(1) mRNA. The findings are consistent with a role for PACAP both in nociception and regeneration.
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| 7. |
- Uddman, Rolf, et al.
(författare)
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Neuropeptide expression in the human trigeminal nucleus caudalis and in the cervical spinal cord C1 and C2.
- 2002
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Ingår i: Cephalalgia. - : SAGE Publications. - 0333-1024 .- 1468-2982. ; 22:2, s. 112-116
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Tidskriftsartikel (refereegranskat)abstract
- In migraine and other primary headaches there is a strong vascular component. Besides the trigeminovascular components some of the associated symptoms point to the involvement of brain stem regions. The central limb of the trigeminal vascular pathway is its projection to the trigeminal nucleus caudalis (TNC) and to the C1-C2 levels of the spinal cord. The aim of the present study was to demonstrate the occurrence of some neurotransmitters in these regions in man. In both the TNC and in the Rexed's laminae I and II of the dorsal horns at the C1 and C2 levels there were numerous substance P immunoreactive fibres. Fibres containing calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating peptide (PACAP) were moderately dense in number. Fibres containing vasoactive intestinal peptide (VIP) or nitric oxide synthase (NOS) were not seen in the TNC or at the C1 and C2 levels of the spinal cord.
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