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)

Vasoactive intestinal polypeptide (VIP)-immunoreactive nerves have been demonstrated in close association with the islets of Langerhans, and VIP has been shown to stimulate insulin and somatostatin secretion. Using [125I]VIP and membranes prepared from rat insulinoma (RIN) cells, i.e., the subclones m5F (m5F; mainly insulin-secreting) and 14B (14B; mainly somatostatin-secreting), it was found that VIP (10(-10)-10(-7) M) competitively inhibited the binding of [125I]VIP. A single class of high affinity binding sites with Kd values of 0.40 +/- 0.06 nM and 0.36 +/- 0.08 nM for m5F and 14B, respectively, with a corresponding number of binding sites (Bmax) of 163 +/- 20 and 254 +/- 51 fmol/mg protein was observed. The rank order of potency in inhibiting [125I]VIP binding was in both cell lines: VIP greater than helodermin greater than pituitary adenylate cyclase activating polypeptide 1-27 (PACAP27) greater than peptide histidine isoleucine (PHI) greater than secretin. VIP caused a dose-dependent increase in cAMP-formation in both m5F and 14B cell membranes with EC50 values of 3.0 and 3.5 nM, respectively, but VIP (1.10(-9)-3.10(-6) M) had no effect on insulin secretion (over 2 h) from the m5F cells. Thus, the data suggest that the VIP-receptors in these neoplastic rat cell lines, despite an apparent coupling to adenylate cyclase activity, seem to be functionally uncoupled to an effect on insulin secretion following an acute exposure to VIP.
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PMID:Demonstration of [125I]VIP binding sites and effects of VIP on cAMP-formation in rat insulinoma (RINm5F and RIN14B) cells. 133 38

A somatostatin receptor isolated from GH4C1 rat pituitary tumor-derived cells was cleaved with cyanogen bromide or cyanogen bromide+trypsin to obtain sequenceable fragments. Five unique amino acid sequences ranging from 6 to 27 amino acid residues were obtained. The sequence was identical to sequence recently reported for one of two somatostatin receptors cloned from human pancreas [Yamada et al., (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 251-255] except for a single valine to isoleucine substitution. This is the first report of amino acid sequence from a purified somatostatin receptor.
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PMID:Partial amino acid sequence of a somatostatin receptor isolated from GH4C1 pituitary cells. 134 34

The present studies were directed to determine whether peptide histidine isoleucine (PHI) affects expression of the gastrin and somatostatin genes and whether such effects may be functionally linked. In separate experiments, the effects of PHI on medium gastrin and somatostatin concentrations, the incorporation of 35S-labelled amino acids into newly synthesized gastrin and somatostatin, and steady state gastrin and somatostatin mRNA were determined. PHI inhibited basal expression of the gastrin gene at all levels examined, while no significant effect on basal somatostatin gene expression could be detected. PHI also decreased carbachol-stimulated antral gastrin release and simultaneously increased somatostatin release. However, in contrast to its structural analogues, secretin and gastric inhibitory peptide, the immunoneutralization of endogenous somatostatin by the administration of specific antibodies did not affect significantly the capacity of PHI to inhibit gastrin release into the culture medium stimulated by carbachol. The results of these studies indicate that PHI exerts a physiological inhibitory effect on antral gastrin cells and that this inhibition may occur at several steps along the biosynthetic pathway. In addition, unlike its structural analogues, PHI inhibition of carbachol-stimulated gastrin release is not functionally linked to its stimulatory effects on somatostatin release.
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PMID:The effects of peptide histidine isoleucine on antral gastrin and somatostatin. 135 64

By means of immunohistochemistry and radioimmunoassay (RIA), we have investigated the possible occurrence of somatostatin (SOM)-like immunoreactivity (-LI) in the autonomic innervation of the pig nasal mucosa. SOM-immunoreactive (-IR) fibres were present around nasal arteries, arterioles and venous sinusoids. Double-labelling experiments revealed that SOM-LI was co-localized with the noradrenaline (NA) markers tyrosine hydroxylase and dopamine-beta-hydroxylase as well as with neuropeptide Y (NPY) in a subpopulation of neurons in the superior cervical sympathetic ganglion and in perivascular nerve terminals. Furthermore, SOM-LI was also present in perivascular fibres containing vasoactive intestinal polypeptide (VIP) and NPY of presumably parasympathetic origin. The parasympathetic fibres that were associated with glands contained peptide histidine isoleucine (PHI), VIP and NPY but not SOM, suggesting that in the nasal mucosa SOM-IR is restricted to perivascular nerves. As revealed by RIA, the content of SOM-LI in biopsies of both nasal mucosa and superior cervical sympathetic ganglion was about 12 pmol/g and the reverse phase HPLC characterisation of SOM-LI shown two separate peaks for SOM-28 and SOM-14. In thiopentone anaesthetized pigs (n = 10), local intra-arterial (i.a.) infusion of SOM (1-14) induced dose-dependent, long lasting and parallel reduction of the nasal arterial blood flow, the volume of the nasal mucosa (reflecting capacitance vessel function) and decrease of the laser Doppler flowmeter signal (reflecting superficial nasal mucosal blood flow). These functional responses were not modified after pretreatment with the alpha-adrenoceptor antagonist phenoxybenzamine (1 mg kg-1 i.a.) whereas the effects of NA were almost abolished. SOM (6.10(-6) mol, i.a.) did not influence the nasal vascular responses to single impulse stimulation of the nasal sympathetic nerve supply providing no evidence for prejunctional activity in spite of clear-cut vascular effects. It is concluded that SOM-LI is co-localized with NA and NPY in sympathetic nerves and with VIP/NPY in parasympathetic perivascular nerves of the pig nasal mucosa. Since SOM evokes vasoconstriction via non-adrenergic mechanisms, this peptide should also be considered when discussing mediator candidates for the neural regulation of the nasal vascular bed.
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PMID:Vascular control of the pig nasal mucosa: distribution and effect of somatostatin in relation to noradrenaline and neuropeptide Y. 135 11

An implanted stimulating device chronically stimulated the left cervical vagus nerve in epileptic patients. Cerebrospinal fluid concentrations of free and total gamma-aminobutyric acid, homovanillic acid, 5-hydroxyindoleacetic acid, aspartate, glutamate, asparagine, serine, glutamine, glycine, phosphoethanolamine, taurine, alanine, tyrosine, ethanolamine, valine, phenylalanine, isoleucine, vasoactive intestinal peptide, beta-endorphin, and somatostatin were measured before and after 2 months of chronic stimulation in six patients. Significant increases were seen in homovanillic acid and 5-hydroxyindoleacetic acid in three patients, and significant decreases in aspartate were seen in five patients. These changes were associated with a decrease in seizure frequency.
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PMID:Neurochemical effects of vagus nerve stimulation in humans. 150 37

A novel metallo-endopeptidase from human neuroblastoma NB-OK-1 cells was partially purified and characterized. This enzyme activity was detected in the culture medium and could be detached from intact cells by gentle washing, suggesting a peripheral localization of the enzyme. This endopeptidase inactivated Atrial Natriuretic Peptide (ANP) by a unique and selective cleavage of the Ser123-Phe124 bond. It also produced hydrolysis at the Xaa-Phe, Xaa-Leu, or Xaa-Ile bonds of other peptide hormones such as bradykinin, somatostatin 14, litorin, substance P, neuromedin C and angiotensin II. The substrate selectivity and inhibition profile of the enzyme showed obvious similarities with the peptide hormone inactivating endopeptidase (PHIE) recently purified from Xenopus laevis skin secretions and indicated a thermolysin-like activity distinct from neutral endopeptidase (EC 3.4.24.11) and from angiotensin converting enzyme (EC 3.4.15.1).
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PMID:A new metallo- endopeptidase from human neuroblastoma NB-OK-1 cells which inactivates atrial natriuretic peptide by selective cleavage at the Ser123-Phe124 bond. 153 Oct 11

The occurrence and distribution of an array of neuropeptides and dopamine-beta-hydroxylase in the circumvallate papillae of monkey, pig, cow, ferret, cat, rat and mouse was studied by immunocytochemistry. The animals were chosen to represent species with different diets. Substance P/neurokinin A- and calcitonin gene-related peptide-containing fibers were numerous in the circumvallate papillae of all animals examined, with the highest frequency in monkey, pig, cow, rat and mouse; in ferret and cat moderate numbers were detected. Vasoactive intestinal peptide/peptide histidine isoleucine amide-containing fibers were numerous in the circumvallate papillae of pig, while they were moderate in number in monkey, ferret and mouse. Neuropeptide Y-containing fibers were few to moderate in number in the circumvallate papillae of all species. Galanin-containing fibers were numerous in the pig circumvallate papillae, while only a few fibers could be detected in monkey, cow, cat, rat and mouse. Somatostatin-containing fibers were seen only in the cat circumvallate papillae, gastrin-releasing peptide-containing fibers in the cow and cat, cholecystokinin/gastrin-containing fibers in the pig and cow. Dopamine-beta-hydroxylase-containing fibers were detected in all animals studied. They were few to moderate in number in the circumvallate papillae. There was no obvious link between the peptidergic innervation pattern and the food habits.
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PMID:Peptide-containing nerve fibers in the circumvallate papillae. 169 15

The localization and distribution of seven neuropeptides in the nervous system of the plerocercoid, adult and free proglottis stages of the tetraphyllidean tapeworm Trilocularia acanthiaevulgaris have been determined by an indirect immunofluorescence technique. Six of the peptides are vertebrate-derived, namely, pancreatic polypeptide (PP), peptide tyrosine tyrosine (PYY), vasoactive intestinal polypeptide (VIP), peptide histidine isoleucine (PHI), substance P (SP) and somatostatin (SRIF); the seventh is the invertebrate neuropeptide, FMR Famide. This is the first demonstration of VIP and SP immunoreactivity in a cestode parasite, and for SRIF this is its first description in any parasitic platyhelminth. Cell bodies and nerve fibres immunoreactive to PP, PYY, VIP, SP and FMRFamide are present throughout the CNS; the distributions of PHI and SRIF were more restricted. In the PNS, nerve fibres immunoreactive to PP occur in the bothridia, whilst in the free proglottis nerve fibres immunoreactive to PYY and VIP innervate the gonads; VIP-immunoreactive nerve elements also supply the reproductive ducts. Extra-neuronal sitings of peptide immunoreactivities were evident for PHI, in association with the excretory system, and for SRIF, in presumed tegumental cell bodies in the free proglottis. The results are discussed in relation to the possible roles of the peptides in the neurophysiology and developmental biology of the worm.
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PMID:Peptidergic nerve elements in three developmental stages of the tetraphyllidean tapeworm Trilocularia acanthiaevulgaris. An immunocytochemical study. 169 77

Immunocytochemical double and triple staining techniques were employed on whole mounts of the submucosal plexus from normal Wistar and non-diabetic BB rat jejunum and ileum, to determine the patterns of co-localization of vasoactive intestinal polypeptide-, peptide histidine-isoleucine-, somatostatin-, neuropeptide Y-, calcitonin gene-related peptide-, substance P-, and galanin-immunoreactive nerves. Neuropeptide Y immunoreactivity was found in 38% of submucosal plexus neurons, within the same neuronal elements as vasoactive intestinal polypeptide immunoreactivity (39% of submucosal plexus neurons) and peptide histidine-isoleucine immunoreactivity. A small population (1% of submucosal plexus neurons) containing vasoactive intestinal polypeptide- and peptide histide isoleucine-like immunoreactivity without NPY-like immunoreactivity was also observed. A significant population of fibers containing vasoactive intestinal polypeptide and galanin immunoreactivity were observed in the mucosa and submucosa, although no cell bodies were detected which contained both neuropeptides. Galanin-like immunoreactivity was seen in a small (2% of submucosal plexus neurons) population, not co-localized with any of the other neuropeptides examined. All somatostatin-immunoreactive neuronal elements (18% of submucosal plexus neurons) contained calcitonin gene-related peptide immunoreactivity, just over half of which also contained substance P immunoreactivity. An additional 25% of submucosal plexus neurons contained calcitonin gene-related peptide- without somatostatin-like immunoreactivity and 28% of submucosal plexus neurons contained substance P without somatostatin-like immunoreactivity. Some degree of co-localization was seen between calcitonin gene-related peptide- and substance P-like immunoreactivity, however, this could not be directly quantified.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The co-localization of neuropeptides in the submucosa of the small intestine of normal Wistar and non-diabetic BB rats. 169 58

Light microscopic immunocytochemistry was utilized to localize populations of neurons in the human retina immunoreactive for the following neuroactive peptides: substance P (SP), vasoactive intestinal polypeptide (VIP), somatostatin (SOM) and LANT-6-(H-Lys-Asn-Pro-Tyr-Ile-Leu-OH), a hexapeptide which is identical to the C-terminal half of neurotensin except for the amino acid substitutions Lys/Arg and Asn/Arg. The majority of SP immunoreactive cells were amacrine cells whose pear-shaped or oval cell bodies (about 8 microns in diameter) were situated in the proximal parts of the inner nuclear layer. A small number of SP-stained somas (about 10-15 microns in diameter) were located in the ganglion cell layer and were designated as those of displaced amacrine cells. The SP-immunoreactive processes were distributed in sublamina 1, 3 and 5 with the most dense plexus being found in sublamina 3 of the inner layer. VIP-positive cell bodies (8-9 microns) were oval or pear-shaped and were situated in the innermost cell rows of inner nuclear layer. The majority of fine VIP-immunoreactive processes extended to sublamina 3 with only a few branches distributing in sublamina 1 of the inner plexiform layer. The SOM-stained cell bodies (10-11 microns) were round and were situated in the innermost cell rows of inner nuclear layer. SOM-positive processes were observed in sublamina 1 and 2 of the inner plexiform layer. The LANT-6 immunoreactive cell bodies (12-22 microns) were either oval-, round- or pyriform-shaped and were situated in ganglion cell layer.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Localization of neuropeptide-immunoreactive neurons in the human retina. 169 34


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