Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01350 (gastrin)
 9,683 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An enkephalin analogue [D-Ala2, MePhe4, Met(o)-ol] enkephalin (DAMME), given intravenously to normal subjects raised serum prolactin and growth-hormone levels but lowered serum levels of luteinising hormone, follicle-stimulating hormone, cortisol, and corticotrophin. There was also a small fall in total glucagon and gastric inhibitory peptide (G.I.P.) and a rise in thyrotrophin. beta-Lipotrophin, motilin, vasoactive intestinal peptide, insulin, gastrin, and pancreatic glucagon were unchanged. Blood-glycerol increased, and blood lactate, alanine, and glucose fell. Prior administration of the opiate antagonist, naloxone, attenuated the hormonal responses to DAMME. This enkephalin analogue produces endocrine and metabolic changes in man which may be mediated through opiate-binding receptors both within and outside the brain. The enkephalins and related substances may provide an important link between perception, behaviour, and neuroendocrine regulation of hormone secretion and metabolism.
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PMID:Hormonal and metabolic responses to an enkephalin analogue in normal man. 8 35

We have used a specific deoxyoligonucleotide probe to detect gastrin mRNA in poly(A)-enriched RNA preparations from hog antrum. The nucleotide sequence of the oligonucleotide, d(C-T-C-C-T-C-C-A-T-C-C-A), was deduced from the unique amino acid sequence Trp-Met-Glu-Glu of gastrin. When used with hog antral RNA, the dodecanucleotide is an effective primer for the synthesis of gastrin-specific cDNA as judged by nucleotide sequence analysis of cDNA isolated by polyacrylamide gel electrophoresis. We have determined an 81-nucleotide sequence corresponding to the region of the gastrin mRNA that codes for the known amino acid sequence of the G34 progastrin intermediate species, and we have demonstrated the presence of two consecutive basic residues preceding the G34 sequence in the prohormone. Hybridization of gastrin cDNA or synthetic dodecanucleotide to hog antral RNA separated by gel electrophoresis on agarose gels in the presence of methylmercuric hydroxide indicates that the mRNA coding for gastrin is about 620 nucleotides long. These results suggest that the gastrin precursor peptide contains 110-140 amino acids. This method should be of general application for detection and characterization of mRNAs corresponding to proteins of known amino acid sequence.
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PMID:Detection and partial sequence analysis of gastrin mRNA by using an oligodeoxynucleotide probe. 8 48

We have prepared 125I-labeled physalaemin and have examined the kinetics, stoichiometry, and chemical specificity with which the labeled peptide binds to dispersed acini from guinea pig pancreas. Binding of 125I-labeled physalaemin was saturable, temperature-dependent, and reversible and reflected interaction of the labeled peptide with a single class of binding sites on the plasma membrane of pancreatic acinar cells. Each acinar cell possessed approximately 500 binding sites, and binding of the tracer to these sites could be inhibited by physalaemin [concentration for half-maximal effect (Kd), 2 nM], substance P (Kd, 5 nM), or eledoisin (Kd, 300 nM) but not by cholecystokinin, caerulein, bombesin, litorin, gastrin, secretin, vasoactive intestinal peptide, glucagon, somatostatin, neurotensin, bovine pancreatic polypeptide, leucine-enkephalin, methionine-enkephalin, atropine, or carbamylcholine. With physalaemin, substance P, and eledoisin, there was a close correlation between the relative potency for inhibition of binding of labeled physalaemin and that for stimulation of amylase secretion. For a given peptide, however, a 3-fold higher concentration was required for half-maximal inhibition of binding than for half-maximal stimulation of amylase secretion, calcium outflux, or cyclic GMP accumulation. These results indicate that dispersed acini from guinea pig pancreas possess a single class of receptors that interact with physalaemin, substance P, and eledoisin and that occupation of 45% of these receptors will cause a maximal biological response.
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PMID:Interaction of physalaemin, substance P, and eledoisin with specific membrane receptors on pancreatic acinar cells. 23 Apr 88

The indirect immunofluorescence technique was used to demonstrate a substance reacting with gastrin antisera in the brain of Xenopus laevis. Immunoreactive material was found in two sites: (1) In the caudal hypothalamus more precisely in the nucleus infundibularis ventralis, (NIV) of the pars ventralis of the tuber cinereum, (PVTC). The fluorescent axons of the reactive parikarya of the NIV give rise to two symmetrical tracts which run rostro-ventrally and join, in the infundibular floor, the preoptico-hypophysial tract, where they form an uneven median tract coursing caudally and running along the medio-tuberal area before entering the external zone of the median eminence. (2) In the anterior preoptic area (APOA), where numerous nerve fibers and endings form a dense network near the preoptic recess. The exact origin of these terminals has not yet been determined. Control of immunohistochemical specificity shows that the labeling by gastrin antisera is suppressed by gastrin (2--17), but also by cholecystokinin (CCK) and pentagastrin (Peptavlon). These results indicate that the immunoreactive substance revealed belongs to the gastrin group and has an antigenic determinant composed of the amino acid sequence or a protion thereof common to gastrin, CCK and Peptavlon (Trp-Met-Asp-Phe). It should be emphasized that, in the brain of Xenopus laevis, both gastrin-immunoreactive sites correspond to the sites of uptake of steroid hormones (Kelley et al., 1975; Morrell et al., 1975).
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PMID:Immunohistochemical localization of a gastrin-like peptide in the brain of an amphibian, Xenopus laevis Daud. 38 28

Evidence is presented that minigastrin is the C-terminal tetradecapeptide amide of gastrin and not the tridecapeptide amide as previously reported. Synthesis of the tetradecapeptide amide sequence, Trp-Leu-[Glu]5-Ala-Tyr-Gly-Trp-Met-Asp-Phe-Nh2, was achieved by a series of fragment couplings which were mediated by the dicyclohexylcarbodiimide procedure in presence of either N-hydroxysuccinimide or 1-hydroxybenzotriazole. Purification of all intermediate fragments, and of the final protected tetradecapeptide amide, was by Sephadex LH-20 chromatography. Removal of the protecting groups was effected by treatment with 90% trifluoroacetic acid in the presence of a large excess of scavengers. Purification by ion-exchange chromatography afforded the pure tetradecapeptide amide. This material had full physiological activity.
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PMID:Minigastrin; corrected structure and synthesis. 76 48

Two derivatives of the C-terminal tripeptide of gastrin devoid of -NH2 from the phenylalanyl residue and of -COOH from the aspartic acid, MBOC-Met.Asn.Phe-OH (I) and MBOC-Met.Asp-OBenz.Phe-OMe (II), stimulated gastric acid secretion in the dog when infused intravenously at doses of 100 to 400 mug/kg-hr. Maximal responses induced by I and II were about 30-40% of that induced by the C-terminal tetrapeptide of gastrin. At a dose of 600 mug/kg-hr, I had an inhibitory action while II initially augmented and then inhibited acid production. Neither the C-terminal amide nor the carboxyl group of the aspartyl residue is essential for the gastric stimulatory activity of gastrin peptides.
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PMID:Dispensability of both the amide of phenylalanine and the carboxyl group of aspartic acid for the stimulation of gastric acid secretion by gastrin peptides in dogs. 83 7

Tertiary structures of gastrin-like tetrapeptide Trp-Met-Asp-Phe-NH2 and those substituted by Leu, Val or Gly for Met are studied. The lowest energy conformations of the side chains when the back bone is fixed in alpha-helix are obtained by modified minimization algorithm. It is suggested that protein folding proceeds in the accessible conformation space as a self-organization process leading to minimum energy conformation in this space.
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PMID:Tertiary structures of gastrin-like tetrapeptides. 99 44

High-resolution gel chromatography monitored by a sensitive radioimmunoassay for gastrin has disclosed that gastrin circulates in twenty different components. Since the assay is specific for the biological active sequence of gastrin (-Trp-Met-Asp-PheNH2), we conclude that all the twenty circulating molecular forms of gastrin encountered in this study may participate in the regulation of gastric acid secretion. There are two dominating forms of gastrin in serum: gastrin-34-like components and gastrin-17-like components. The former constituted 60% and the latter constitutes approximately 30% of the immunoreactive gastrins. We suggest that extragastrointestinal conversion of gastrin-17, released from tissue, is an important source of gastric-34-like components. Such conversion has been observed in intact man and pig. Studies with the isolated perfused porcine liver indicate that the liver is important in the metabolism of gastrin-17, and that conversion may be a hepatic function.
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PMID:The heterogeneity of gastrin, with reference to conversion of gastrin-17. 105 77

The term cholecystokinin (CCK) refers to a family of related peptides whose members play hormonal roles in the gastro-intestinal tract. The sulfated octapeptide CCK-8 [Asp-Tyr(SO3H)-Met-Gly-Trp-Met-Asp-Phe-NH2] is also abundant throughout the central nervous system where it satisfies the criteria for a neurotransmitter. CCK interacts with at least two types of receptor called CCK-A and CCK-B receptors. These binding sites can be distinguished on the basis of their affinities for different molecular forms of CCK. Moreover, selective nonpeptide antagonists have been developed for CCK-A and CCK-B receptors. CCK-A receptors occur predominantly at the peripheral level where they are responsible for the digestive effects of CCK: intestinal and biliary smooth muscle contraction, pancreatic enzyme secretion, trophic effects on gastric and intestinal mucosa and regulation of feeding. Some brain CCK-receptors belong to the A-type, but the majority of them are CCK-B receptors. High densities of brain CCK-B receptors are present in cortical and limbic areas such as the amygdala and the hippocampus. At the peripheral level, CCK-B receptor antagonists are active on gastrin receptors, and these two receptors are similar if not identical. Experimental evidence suggests involvement of brain CCK processes in 4 domains: modulation of dopaminergic function, control of pain sensation, anxiety and memory formation. Thus, CCK-B antagonists may be useful to treat certain neuropathological conditions associated with CCK dysfunction.
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PMID:[Cholecystokinins and their receptors. Functional aspects]. 130 46

Studies demonstrate that some colon cancers possess receptors for various gastrointestinal hormones or neurotransmitters, the occupation of which can affect growth. These results are limited because frequently only a small number of tumors are studied, only 1 or 2 receptors are sought, and the effect on cell function is not investigated. In the present study, 10 recently characterized human colon cancer cell lines were studied to determine whether they possess receptors for any of 12 different gastrointestinal hormones or neurotransmitters and to determine whether these receptors mediate changes in cellular function. Each of the cell lines exhibited receptors for at least one radioligand. Receptors for vasoactive intestinal peptide (VIP) and muscarinic cholinergic agents occurred on 60%, bombesin and gastrin on 30%, beta-adrenergic agents and gastrin-releasing peptide (GRP) on 20%, and somatostatin, opiates, neuromedin B, and substance P on 10%. Analysis of [3H]N-methylscopolamine binding revealed a Kd of 0.2 nM for N-methylscopolamine with a binding capacity of 2500 sites/cell. With the agonist carbamylcholine, the receptor exhibited 2 classes of binding sites: one of high affinity (Kd 55 microM) representing 75% of the binding sites and one of low affinity (Kd 0.3 mM) representing 25% of the binding sites. Analysis of 125I-[Tyr4]bombesin binding revealed a receptor of high affinity (Kd 2.1 microM) with a binding capacity of 3300 sites/cell. Inhibition of binding by agonists revealed relative potencies of 125I-[Tyr4]bombesin greater than GRP much greater than neuromedin B, and two recently described antagonists were similar in potency to GRP. Analysis of 125I-VIP binding revealed a receptor having 2 classes of binding sites: one of high affinity (Kd 3.6 nM) and one of low affinity (Kd 1.7 microM) which represented the majority of the 5.5 x 10(6) binding sites/cell. The relative potencies of agonists were VIP greater than helodermin greater than peptide histidine methionine greater than secretin. Evaluation of biological activity mediated by the muscarinic cholinergic and bombesin receptors revealed an increase of intracellular calcium and of inositol triphosphate by specific receptor agonists. The presence or absence of receptors detected by binding correlated closely with the ability of selective receptor agonists to alter cell function. These results demonstrate the presence of several different receptors for gastrointestinal hormones or neurotransmitters, some described for the first time, on human colon cancer cell lines, including bombesin-related peptides, VIP, somatostatin, substance P, beta-adrenergic agents, calcitonin gene-related peptide, gastrin, muscarinic cholinergic agents, and opiates.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Characterization of functional receptors for gastrointestinal hormones on human colon cancer cells. 131 Jun 40


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