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)

The physiological regulation of intestinal proglucagon-derived peptide secretion has not been well studied. We have therefore used a fetal rat intestinal cell culture model to investigate the control of secretion of the gut glucagon-like immunoreactive (GLI) peptides by other intestinal regulatory peptides in vitro. Secretion of the intestinal GLI peptides was found to be stimulated in a dose-dependent fashion by the intestinal endocrine peptide, gastric inhibitory peptide (at greater than or equal to 10(-10) M, P less than 0.05), and by the neurocrine peptides, gastrin-releasing peptide (at greater than or equal to 10(-12) M, P less than 0.05), and calcitonin gene-related peptide (at greater than or equal to 10(-8) M, P less than 0.05). Gastrin-releasing peptide and its amphibian equivalent, bombesin were equipotent in stimulating GLI peptide secretion. In contrast, the endocrine and neurocrine intestinal somatostatin-related peptides, somatostatin-28 and -14, inhibited release of the GLI peptides, at concentrations of 10(-10) (P less than 0.01) and 10(-8) (P less than 0.01) M, respectively, with significant differences in potency between the two peptides detected at 10(-10) M (P less than 0.05). The inhibitory effects of both somatostatin-28 and -14 could be blocked by preincubation of the cells with pertussis toxin (P less than 0.05). Dose-dependent stimulation of gut GLI peptide secretion was also detected in response to treatment of cultured cells with sodium oleate (at 10(-4) M; P less than 0.05), or with the cholinergic agonist bethanecol (at greater than or equal to 100 microM; P less than 0.05). Other endocrine [cholecystokinin, glucagon, glucagon-like peptide-1(1-37), glucagon-like peptide-1(7-37), glucagon-like peptide-2, neurotensin, and peptide YY] and neurocrine (vasoactive intestinal peptide) peptides, and the synthetic glucocorticoid, dexamethasone, were without effect on secretion of the gut GLI peptides, at doses of 10(-12) to 10(-6) M. The results of the present study therefore demonstrate that secretion of the intestinal proglucagon-derived peptides is under the regulatory control of a wide variety of intestinal endocrine and neurocrine peptides, as well as nutrients (fats) and neurotransmitters (acetylcholine).
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PMID:Regulation of intestinal proglucagon-derived peptide secretion by intestinal regulatory peptides. 167 88

Delta-sleep-inducing peptide (DSIP), vasoactive intestinal peptide (VIP), peptide YY (PYY) and somatostatin (SOM) were assayed with specific radioimmunological methods in cerebrospinal fluid (CSF) of healthy volunteers, 12 patients with Alzheimer's disease (AD), 11 patients with multi-infarct dementia (MID) and 10 patients with normal-pressure hydrocephalus (NPH). Patients with NPH were reinvestigated 3 months after a ventriculoperitoneal shunt operation. DSIP, PYY and SOM levels in CSF were decreased in patients with NPH compared to controls. The CSF concentration of SOM was also significantly reduced in patients with AD. No correlations were found between the degree of dementia in any of the illnesses and the CSF concentrations of the peptides. The concentration of DSIP, VIP and SOM increased significantly in parallel to the clinical improvement after the shunt operation in NPH patients.
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PMID:Neuropeptides in cerebrospinal fluid in normal-pressure hydrocephalus and dementia. 167 71

In light of the effects of gastrointestinal (GI) peptides on bile secretion and biliary tract mobility, we studied the effects of GI peptides on gallstone formation in guinea pigs fed on low protein lithogenic diet. The peptides under study included cholecystokinin octapeptide (CCK-8), vasoactive intestinal peptide (VIP), somatostatin (SRIF), secretin (SEC), and neurotensin (NT). Hepatic bile flow, electrolytes, and other bile components were also measured. It was found that CCK-8 and VIP suppressed the formation of gallstones and increased hepatic bile flow and Na+, K+, Cl- output significantly. On the other hand, SRIF significantly promoted gallstone formation. The rates of gallstone formation in CCK-8, VIP, and SRIF treated guinea pigs were 15.4%, 23.5%, and 88.0%, respectively, in contrast to 56.8% in the control group. The inhibitory effect of CCK-8 and promoting effect of SRIF on gallstone formation were dose-dependent.
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PMID:Effects of gastrointestinal peptides on formation of gallstone in guinea pigs. 167 24

The direct action of somatostatin on smooth muscle was examined in muscle cells isolated from the stomach and intestine of human and guinea pig. Somatostatin inhibited relaxation in gastric but not intestinal muscle cells of the two species, and its mechanism of action was explored in more detail in gastric muscle cells of the guinea pig. Somatostatin inhibited relaxation induced by vasoactive intestinal peptide (VIP, 83 +/- 7%, P less than 0.001) and isoproterenol (85 +/- 5%, P less than 0.001), as well as the concomitant increase in adenosine 3',5'-cyclic monophosphate (cAMP) production [81 +/- 25% inhibition with VIP (P less than 0.02) and 68 +/- 12% inhibition with isoproterenol (P less than 0.01)]. Inhibition of relaxation and cAMP production was abolished by pretreatment of the cells with pertussis toxin. Relaxation induced by the permeant derivative of cAMP, N6,2'-O-dibutyryladenosine 3',5'-cyclic monophosphate, by sodium nitroprusside, which acts by increasing levels of guanosine 3',5'-cyclic monophosphate, or by ATP, which acts by opening of K+ channels, was not affected by somatostatin. The fact that inhibition by somatostatin and its reversal by pertussis toxin was confined to agonists that stimulate an increase in the levels of cAMP implied that somatostatin acts by inhibiting the generation and not the action of cAMP. It is concluded that somatostatin receptors on gastric muscle cells mediate inhibition via a GTP-binding, pertussis-sensitive regulatory protein, Gi, coupled to adenylate cyclase.
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PMID:Inhibition of muscle cell relaxation by somatostatin: tissue-specific, cAMP-dependent, pertussis toxin-sensitive. 167 35

Cyclic AMP production in response to agonists which act at a variety of receptors to either stimulate or inhibit cyclic AMP production has been studied in intact, dissected ciliary processes from rabbit eyes after unilateral surgical removal of the cervical ganglion. Cyclic AMP responses to stimulatory ligands vasoactive intestinal peptide (VIP), isoproterenol, and forskolin and inhibitory agonists neuropeptide Y (NPY), the synthetic somatostatin analogue SMS 201-995, and alpha-adrenergic agents were investigated in tissues from normal eyes and compared to the same responses in tissues from sympathetically denervated eyes. Neither stimulated cyclic AMP production nor inhibition of stimulated cyclic AMP production was significantly different in tissues from denervated vs. normal eyes. Inhibition of VIP-stimulated cyclic AMP production by epinephrine and paraaminoclonidine in tissues from both normal and denervated eyes was blocked by the alpha 2-adrenergic antagonist yohimbine but not by the alpha 1-adrenergic antagonist prazosin. These data indicate that the VIP, NPY, somatostatin, and alpha 2- and beta 2-adrenergic receptors which regulate cyclic AMP production in rabbit ciliary processes are postjunctional and suggest that ligands known to modulate cyclic AMP levels in this tissue may exert effects on aqueous humor formation independently of adrenergic innervation.
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PMID:Stimulatory and inhibitory cyclic AMP responses in rabbit ciliary processes after cervical ganglionectomy. 167 9

The anterior major pelvic ganglion (AMPG) of the male guinea-pig has been found to consist of three principal components. The presence of a cholinergic component was determined by the demonstration of cytoplasmic and nerve fibre acetylcholinesterase activity. A noradrenergic component was demonstrated by immunoreactivity (IR) of the catecholamine-synthesising enzymes tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase (DBH) in neuronal perikarya. The AMPG also had a peptidergic component which may or may not sub-classify the cholinergic and noradrenergic components. Neuropeptide Y (NPY)-, vasoactive intestinal peptide (VIP)-, and atrial natriuretic factor (ANF)-immunoreactivities were seen in neuronal perikarya, nerve fibres and nerve terminals/varicosities, while somatostatin (SOM)-IR was restricted to neuronal perikarya. Substance P (SP)-IR was present in a dense network of varicose nerve fibres. However, on a rare occasion SP-IR was observed in neuronal perikarya. Enkephalin (ENK)-IR occurred in a sparsely distributed plexus of varicose nerve fibres. The analysis of adjacent serial sections demonstrated distinct patterns of neuropeptide coexistence in AMPG neurons. NPY-IR was colocalised to a subpopulation of TH-IR neuronal perikarya. NPY-IR was also colocalised with VIP-IR in non-TH-IR neuronal perikarya. VIP-IR occurred together with AChE in particular neuronal perikarya. The relationship between immunoreactive neuronal perikarya and immunoreactive nerve terminals was investigated. SP-IR nerve terminals were closely related to neuronal perikarya exhibiting VIP-, NPY-, or TH-IR. TH-IR neuronal perikarya were also abutted by ENK-IR nerve terminals. VIP- and NPY-immunoreactive neuronal perikarya were abutted by two nerve terminal types: one immunoreactive for VIP, the other for NPY. DBH-IR neuronal perikarya received AChE-positive varicosities while AChE-positive neurons were abutted by DBH-IR varicose nerve fibres. AChE-positive varicosities were also closely related to neuronal perikarya possessing VIP-IR and AChE activity.
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PMID:Specific patterns of immunoreactivity in neuronal elements of the anterior major pelvic ganglion of the male guinea-pig. 168 Aug 42

To determine the possible physiological role of endogenous vasoactive intestinal peptide (VIP) in the control of cerebral somatostatin (SS), we studied the effect of endogenous VIP blockade on immunoreactive SS (IR-SS) accumulation by fetal rat cerebral cortical and hypothalamic cells in culture. Cells were cultured in minimum essential medium (MEM) with 10% fetal calf serum and 10% horse serum. After 7-10 days 'in vitro' media were replaced with MEMs without sera containing anti-VIP immunoglobulins G (IgG) for 1, 3, 6, 24 or 48 h. Controls received the same amount of IgG from normal rabbit serum (NRS). In another group of experiments, cells were incubated with VIP (10(-11) M to 10(-7) M) for 1, 3, 6 or 24 h. Exposure to anti-VIP IgG resulted in a decreased accumulation of IR-SS in both cerebral cortical and hypothalamic cells, whereas the addition of VIP caused a dose-dependent increase in total IR-SS, these effects being evident after 3 h incubation. The stimulatory action VIP on IR-SS was up to 129%, this being decreased to 86% by the addition of anti-VIP to plates containing 10(-7) M VIP. Patterns of IR-SS accumulation throughout prolonged incubation periods were qualitatively similar (in both cerebrocortical and hypothalamic cells) in the presence or absence of anti-VIP IgG. However, in plates containing anti-VIP, the total amount of IR-SS was lower than in the control groups (IgG from NRS). These findings demonstrate that, at this time of brain development, somatostatinergic neurons may be under the physiological regulation of locally produced VIP.
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PMID:Endogenous vasoactive intestinal peptide (VIP) regulates somatostatin secretion by cultured fetal rat cerebral cortical and hypothalamic cells. 168 71

The appearance of somatostatin (SOM)-immunoreactive (IR) and vasoactive intestinal peptide (VIP)-IR neurons in different regions of the embryonic chicken gut was studied by immunostaining wholemounts. The patterns of expression of these peptides in myenteric neurons showed a number of similarities. Both peptides first appeared in the region of the proventriculus-gizzard: SOM at embryonic day (E)4, VIP at E5.5. At later times both peptides were found in positions both rostral and caudal to the gizzard. Both peptides appeared independently in cells at a second site, the cecum of the hindgut: SOM was observed at E6.5 and VIP at E7.5. VIP-IR and SOM-IR cells appear throughout the cecum, then in the rectum, and finally in the ileum. Differences in the patterns of expression were also found. SOM- and VIP-IR neurons appeared at different times along the length of the gut. VIP-IR cells populated the entire gut by E11.5, whereas SOM-IR cells were not present throughout the gut until E13.5. SOM-IR cells appeared in the terminal part of the ganglion of Remak at E4.0. At E6 these SOM-IR cells sent fibers into the wall of the hindgut and later into the midgut. No VIP-IR cells were found in the ganglion of Remak. These findings suggest that neural crest-derived cells first express SOM- and VIP-IR in particular regions of the gut, namely, the proventriculus-gizzard and the cecum. Certain conditions must exist at these sites which favor the expression of these neuropeptides by neural crest-derived cells. The observation of SOM- and VIP-IR cells in the cecum at a stage of development before cells are seen in the ileum supports the concept that sacral neural crest cells contribute precursors for enteric neurons of the avian hindgut.
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PMID:Appearance of somatostatin and vasoactive intestinal peptide along the developing chicken gut. 168 49

Following a multistep extraction and fractionation of sheep and human milk, immunoreactive and biologically active somatostatin (SS) was demonstrated as a constituent of milk. Milk, in contrast to serum, contains only SS-14-like material and not SS-28. HPLC-purified sheep milk somatostatin was found to inhibit both basal and prostaglandin-induced release of growth hormone from cultured rat pituitary cells. The effect was dose-dependent and similar to that of synthetic SS. In order to determine whether SS or vasoactive intestinal peptide (VIP) can be synthesized by the mammary gland we have looked for SS and VIP messenger RNA in rat glands extracted on different days of lactation. No messages for SS or VIP were detected in the mammary gland, whereas, as expected, hybridization signals for alpha-casein were evident. These results suggest that somatostatin and VIP are not synthesized by the mammary gland and are probably concentrated from blood. In other experiments we have demonstrated that one hour after oral administration of labelled somatostatin to rat pups, about 95% of the neuropeptide, extracted from the stomach, is eluted exactly at the same position as the marker peptide. These results suggest that, in contrast to the adult, somatostatin remains intact in the stomach of the neonate and therefore may be absorbed in a biologically active form.
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PMID:Hypothalamic hormones in milk. 168 87

We have investigated the regulation of mRNA levels of alpha- and beta-subunits of guanine nucleotide-binding regulatory proteins (G proteins) by peptide hormones in prolactin producing rat pituitary adenoma cells (GH3 cells) in culture. The cells were treated with thyroliberin (1 microM), vasoactive intestinal peptide (1 microM) or somatostatin (10 microM) for 6 to 48 hours. Thyroliberin and vasoactive intestinal peptide increased the levels of Gs alpha Go alpha, Gi-2 alpha, Gi-3 alpha, Gx alpha, G beta 36 and mRNAs. The effect of vasoactive intestinal peptide was however earlier and more pronounced. Gi-2 alpha mRNA levels showed the quantitatively largest alterations. Somatostatin upregulated Gs alpha and downregulated Go alpha and Gi-2 mRNAs. G protein mRNAs for Gi-2 alpha and Go alpha were increased by exposure of the cells to a medium devoid of serum. We conclude that G protein mRNA levels are subjected to alterations by hormones that act through the corresponding G proteins in the regulation of prolactin synthesis and secretion.
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PMID:Regulation of G protein mRNA levels by thyroliberin, vasoactive intestinal peptide and somatostatin in prolactin-producing rat pituitary adenoma cells. 168 38


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