Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

As neuropeptides may play a role in the electrical kindling model of epileptogenesis, hippocampal somatostatin, Met-enkephalin and cholecystokinin were studied by immunocytochemistry in rats 24 h following full hippocampal kindling (three stage 5 seizures). As control animals we used sham-kindled rats, unoperated rats and rats subjected to a single electroshock-induced seizure. In addition, the distribution of septohippocampal, cholinergic fibers and hippocampal mossy fibers were studied by histochemistry. The important finding was that after kindling there was, as compared to unoperated control, (1) a marked increase of somatostatin immunoreactivity in cell bodies in the dentate hilus and their presumed projections area in the outer parts of the dentate molecular layer, and (2) a marked increase of Met-enkephalin immunoreactivity in hippocampal mossy fiber terminals. We found no evidence of aberrant sprouting of mossy fiber collaterals in the fascia dentata.
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PMID:Increased somatostatin and enkephalin-like immunoreactivity in the rat hippocampus following hippocampal kindling. 197 72

The opioid peptides are potent inhibitors of gastric somatostatin-like immunoreactivity (SLI) secretion from the isolated perfused rat stomach. In addition, inhibition of SLI secretion induced by vagal stimulation is partially blocked by naloxone, indicating that endogenously released opioid peptides probably play a physiological role in the regulation of SLI release. The opioid peptides exert their effects by interacting with a number of different receptor types. In the present study, the effect of the selective delta-opioid receptor agonists [D-Pen2.5]enkephalin and [D-Pen2,L-Pen5]enkephalin and the mu-receptor agonist [D-Ala2, N-methyl (NMe)-Phe4,Gly5-ol]enkephalin on gastric inhibitory polypeptide (GIP)-stimulated SLI secretion from the isolated perfused rat stomach have been studied. Responses to the less selective delta-agonist [D-Ala2,D-Leu5]enkephalin, dynorphins 1-8, 1-13, and 1-17, and the extended enkephalin forms Met-enkephalin-Arg6-Phe7,Met- enkephalin-Arg6-Gly7-Leu8, and Met-enkephalin-Arg6-Arg7-Val8-NH2 (metorphamide), have also been investigated. [D-Ala2,NMe-Phe4,Gly5-ol]enkephalin induced a concentration-dependent inhibition of GIP-stimulated SLI secretion, with 50% of maximal inhibition at 10 nM. Neither [D-Pen2.5]enkephalin nor [D-Pen2,L-Pen6]enkephalin (10 nM to 1 microM) had any effect on SLI release, and [D-Ala2,D-Leu5] enkephalin inhibited SLI release only at high concentrations. Met-enkephalin-Arg6-Phe7 and metorphamide both inhibited SLI release, whereas Met-enkephalin-Arg6-Gly7-Leu8 and the dynorphins had little or no effect. In conclusion, the strong inhibition of SLI secretion produced by [D-Ala2,NMe-Phe4,Gly5-ol] enkephalin and lack of major effect of [D-Pen2.5]-enkephalin, [D-Pen2,L-Pen5]enkephalin, and the dynorphins indicate that opioid peptide-induced inhibition was mediated by interaction with mu-receptors and that neither delta or kappa-receptors play a significant role.
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PMID:Characterization of the opioid receptor type mediating inhibition of rat gastric somatostatin secretion. 197 18

The nature of the genetic defects which define the obese (ob) and diabetes (db) loci in mice remain unknown, but both produce similar syndromes when maintained in the same strain of mice. There is some evidence suggesting a lesion in the central nervous system (CNS) in db/db mice, while ob/ob mice appear to have a primary lesion outside the CNS. In a search for further evidence of a unique central lesion in db/db mice, we have examined neuropeptide content in selected, microdissected brain areas in both of these mutants and lean controls. In order to rule out possible interactions of the db mutation with the genetic background, diabetes mice of both C57BL/KsJ and C57BL/6J strains were studied. When concentrations of nine neuropeptide immunoreactivities were examined in up to seven microdissected areas of the brain, C57BL/6J ob/ob mice showed only one reproducible alteration, a lower content of beta-endorphin-like immunoreactivity (LI) in the preoptic area at both 3 and 6 weeks of age as compared with lean littermates. In contrast, db/db mice of both C57BL/6J and C57BL/KsJ strains exhibited alterations in a total of four peptides in three brain areas: lower concentration of somatostatin-LI in median eminence, higher Met-enkephalin-LI in dorsal vagal complex of the medulla oblongata, higher substance P-LI and lower vasoactive intestinal polypeptide (VIP)-LI in amygdala. The concentrations of the peptides studied in medial basal hypothalamus, lateral hypothalamus, substantia nigra, and preoptic area were not reproducibly altered in db/db mice. These data provide preliminary evidence for unique brain abnormalities in db/db mice in specific areas that are involved in processing of neural signals that can affect the islets of Langerhans, gonadotrophin secretory patterns, and many other visceral functions.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Unique alterations of neuropeptide content in median eminence, amygdala, and dorsal vagal complex of 3- and 6-week-old diabetes mutant mice. 223 77

As part of a series of studies in which we are attempting to determine the roles of the lateral spinal (LSn) and lateral cervical (LCn) nuclei in somatic sensation, we have examined the fibers and terminals within these nuclei in the rat using the indirect immunofluorescence technique. Eleven antisera were used. Within the LSn, antisera against dynorphin 1-8 (DYN), substance P (SP), and Met-enkephalin (ENK) produced labeling of a large number of processes in all segmental levels examined. Processes labeled with these antisera frequently apposed the cell bodies and dendrites of LSn neurons. Antisera against somatostatin (SOM) and FMRF-NH2 (FMRF) labeled smaller numbers of processes within the LSn. Few, if any, processes in the LSn were labeled using antisera against serotonin, cholecystokinin octapeptide, oxytocin, neurotensin, corticotrophin-releasing factor, and vasoactive intestinal polypeptide. In contrast to the LSn, the LCn contained virtually no labeled processes irrespective of the antiserum employed. An area was found adjacent to the LCn in the medial portion of the dorsal lateral funiculus (DLf) of C2 that resembled the LSn in several of its anatomical characteristics: like the LSn, the medial portion of the C2 DLf contained small multipolar neurons; it was similar to the LSn in its medial-lateral extent; and following staining with each antiserum, the LSn and the medial DLf of C2 contained a similar number of labeled processes. The peptide-containing area in the medial DLf of C2 was found to be continuous with the LSn. We therefore propose that this region is a rostral extension of the LSn.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Immunocytochemical studies of the peptidergic content of fibers and terminals within the lateral spinal and lateral cervical nuclei. 241 May 76

The presence and distribution of regulatory peptides in nerves and endocrine cells of the stomach, intestine and rectum of a urodele amphibian, the mudpuppy, Necturus maculosus, was studied immunohistochemically in sections or whole-mount preparations of the gut wall. The effect of the occurring peptides on gut motility was studied in isolated strip preparations of circular and longitudinal smooth muscle from different parts of the gut. Bombesin-, neurotensin-, substance P- and VIP-like immunoreactivity was present in abundant nerve fibres in the myenteric plexus of both stomach, intestine and rectum. Single fibres or bundles were present in the circular muscle layer and in a well-developed deep muscular plexus in the intestine and rectum. Immunoreactive nerve cells were found in the myenteric plexus of the stomach, intestine (neurotensin only) and rectum. Gastrin/CCK-like immunoreactivity was observed only in a few fibres in stomach and rectum. Endocrine cells containing bombesin-, met-enkephalin-, gastrin/CCK-, neurotensin-, somatostatin- or substance P- like immunoreactivity were present in the mucosa. The effect of bombesin was an inhibition of the rhythmic activity in circular muscle preparations and in longitudinal muscle from the rectum, while longitudinal muscle from the stomach usually responded with a weak increase in tonus. Neurotensin, like-bombesin, was inhibitory on the spontaneous rhythmic activity of circular muscle throughout the gut, while the effect on longitudinal muscle was an increase in tonus. Met-enkephalin and substance P increased the tonus of all types of preparations, and often, in addition, initiated a rhythmic activity superimposed on this maintained tonus. VIP had a general inhibitory effect on the preparations, decreasing tonus and/or abolishing rhythmic activity. It is concluded that bombesin-, neurotensin-, substance P- and VIP-like peptides are present in nerves throughout the urodele gut and may have physiological functions in regulating the motility of the gut. The gastrin/CCK-like peptide present in nerves of the stomach and rectum may affect the function of these parts of the gut. The regulatory peptides present in endocrine cells may, perhaps with the exception of the somatostatin-like peptide, affect the motility humorally.
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PMID:Neuropeptides in the gastrointestinal canal of Necturus maculosus. Distribution and effects on motility. 241 14

The effects of the putative neurotransmitters acetylcholine, adrenaline, adenosine, ATP, bombesin, 5-hydroxytryptamine, met-enkephalin, neurotensin, somatostatin, substance P and VIP have been investigated in the perfused intestine of the cod, Gadus morhua. The presence and distribution of the different types of nerves was investigated with immunohistochemistry and Falck-Hillarp fluorescence histochemistry. A spontaneous rhythmic activity of the perfused preparations usually occurred within a few minutes from the start of the experiment. This activity was diminished or abolished by addition of atropine, methysergide or tetrodotoxin to the perfusion fluid. Acetylcholine, 5-hydroxytryptamine or substance P caused a contraction of the intestinal wall. The response to acetylcholine was blocked by atropine but not by tetrodotoxin, while the response to 5-hydroxytryptamine was blocked by methysergide and usually also by tetrodotoxin. This indicates that the effect of acetylcholine is direct on the muscle cells, while the effect of 5-hydroxytryptamine may be at least partly via a second neuron. All adrenergic agonists (adrenaline, isoprenaline and phenylephrine) had a dominating inhibitory effect on the intestine. Experiments with antagonists showed that the inhibition is due to stimulation of both alpha-adrenoceptors and beta-adrenoceptors. ATP, adenosine and somatostatin also caused a relaxation of the intestinal wall, often followed by a contraction. Met-enkephalin produced variable responses, either a relaxation, a contraction or both. Bombesin caused a weak inhibition, if anything. Neurotensin and VIP did not visibly affect the intestinal motility. 5-HT-, substance P- and VIP-like immunoreactivity and catecholamine fluorescence were observed in the myenteric plexus, submucosa and muscle layers in all parts of the intestine.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Neurotransmitters in the intestine of the Atlantic cod, Gadus morhua. 241 59

This study reports on a difference in the inhibitory action of the neuropeptides somatostatin and Met-enkephalin on acetylcholine (ACh) release from myenteric plexus-longitudinal muscle strips of guinea pig small intestine. Met-enkephalin (8.7 X 10(-8) M) inhibited ACh release evoked by either substance P (3.7 X 10(-8) M) or neurotensin (7.5 X 10(-11) M), and this inhibition could be reversed by naloxone (5 X 10(-8) to 5 X 10(-5) M). Neurotensin-induced ACh release was also sensitive to the inhibition by somatostatin. However, when tested in a dose range from 6.1 X 10(-8) to 6.1 X 10(-6) M, somatostatin was ineffective in reducing the efflux of ACh evoked by substance P. These observations provided evidence to support the view that inhibitory peptidergic neurons within the myenteric plexus modulate the activity of cholinergic neurons with a high degree of specificity and that both somatostatin and Met-enkephalin have distinct neuromodulatory functions in the gut.
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PMID:Inhibitory peptidergic neurons: functional difference between somatostatin and enkephalin in myenteric plexus. 241 98

We examined the effects of certain gastrointestinal hormones on gastric motility using rat stomach preparatios in vivo. Changes of water level caused by the movement of the stomach which was filled with saline were recorded. Single injections of cholecystokinin (1, 2 and 4 micrograms/kg) induced relaxation of the stomach. Single injections of bombesin in low doses (below 0.2 microgram/kg) induced relaxation and in high doses (over 0.2 micrograms/kg) contraction after brief relaxation. Single injections of neurotensin (1, 2, 4 and 8 micrograms/kg), somatostatin (5, 10 and 20 micrograms/kg) and substance P (1, 2, 4 and 8 micrograms/kg) induced relaxation followed by contraction, but their dose-response relations were obscure. Infusions of neurotensin (1, 5 and 25 micrograms/kg/h) and somatostatin (2.5 and 5 micrograms/kg/h) enhanced the stomach tension, whereas substance P (1, 5 and 25 micrograms/kg/h) reduced it. Single injections and infusions of neurotensin, somatostatin or substance P showed different effects on gastric motility. On the other hand, Met-enkephalin (1, 10 and 100 micrograms/kg) and porcine motilin (1, 10 and 100 micrograms/kg) did not affect gastric motility in our rat stomach preparations. These results suggest that some gastrointestinal hormones take part in stomach movements.
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PMID:Effects of gastrointestinal hormones and their related compounds on gastric motility in the rat. 241 39

Histochemical methods have been used to study the distribution of putative neurotransmitters in the urinary bladder of newborn guinea-pigs and in cultures of intramural ganglia. Following the nicotinamide adenine dinucleotide (NADH)-diaphorase reaction which specifically labels nerve cell bodies, up to 66 ganglia were observed in stretch preparations of the newborn urinary bladder. Each ganglion contained 2-50 nerve cell bodies. Vasoactive intestinal polypeptide was localized in a few nerve cell bodies of intramural ganglia both in in situ and culture preparations. In the in situ preparations it was widely distributed in nerve fibres to the muscle, being most dense at the base of the bladder, and in some mucosal epithelial cells. Somatostatin was contained in numerous neuronal cell bodies in the detrusor muscle both in situ and in culture. Extensively distributed varicose fibres were found in culture and in the muscle, submucous and mucosal layers in situ. Substance P immunofluorescence was demonstrated in a few neuronal cell bodies in ganglia both in situ and in vitro, particularly in those of the mucosa at the base of the bladder. In the in situ preparations varicose nerve fibres containing substance P were seen in the muscle coats with greatest density in the bladder base. Met-enkephalin-immunoreactive nerve cell bodies were not seen either in situ or in culture. Nerve fibres in in situ preparations were found largely enveloping neuronal cell bodies within the ganglia. Neither serotonin-immunoreactive nor catecholamine-containing neuronal cell bodies were seen in the in situ bladder preparation. However, some nerve cell bodies in culture showed positive staining, possibly as a result of selective uptake of serotonin and catecholamine known to be contained in foetal calf serum in the culture medium or possibly as the result of increased synthetic activity in certain neurones in the culture situation. In whole-mount stretch preparations, no serotonin-immunoreactive nerve fibres were seen, but catecholamine-containing small intensely fluorescent cells and nerve fibres were observed. Acetylcholinesterase-positive nerve cell bodies and nerve fibres were observed both in in situ and culture preparations of the bladder. Quinacrine-positive nerve cell bodies (as an indicator of purinergic neurones) were found in numerous intramural neurones examined. in situ; however, under the culture conditions used, non-selective staining of all cell types occurred.
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PMID:Intramural neurons of the guinea-pig urinary bladder: histochemical localization of putative neurotransmitters in cultures and newborn animals. 242 42

Conditions are described for performing mitogen (Concanavalin A, Con A; lipopolysaccharide, LPS) and mixed lymphocyte reaction (MLR) cultures using serum-free medium. The effects of exogenously adding several gastrointestinal regulatory peptides (beta-endorphin, substance P, met-enkephalin, vasoactive intestinal peptide, bombesin and somatostatin) on the incorporation of 3H-methyl-thymidine was determined. It was observed that mitogen stimulation of lymph node cells with Con A was inhibited (70% of control) by vasoactive intestinal peptide (VIP) but spleen cells stimulated by LPS were insensitive to immunomodulation (98% of control). The ability of VIP to inhibit Con A induced thymidine incorporation was concentration dependent (10(-6) to 10(-18) M) and was not attributable to kinetic shifts or cell toxicity. None of the other tested neuropeptides affected Con A or LPS induced blastogenesis. MLR cultures were inhibited by VIP, beta-endorphin and somatostatin in a biphasic manner with maximal inhibition observed at 10(-8) to 10(-12) M. Both substance P and bombesin exhibited slight immunoenhancing properties at 10(-14) to 10(-18) M. Met-enkephalin was ineffective as an immunomodulator of MLR cultures. The utility of using serum-free medium in identifying neuropeptides with immunomodulatory properties are discussed.
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PMID:Gastrointestinal regulatory peptides modulate mouse lymphocyte functions under serum-free conditions in vitro. 242 44


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