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Biomedical subjects

V Mutt

Publications and source records attributed to V Mutt.

At least 55 records · Page 3Linked to original sources
PubMed1986

Structural requirements for gastric inhibitory polypeptide (GIP) receptor binding and stimulation of insulin release.

The effect of bovine GIP 1-42 and several of its fragments in competing with the binding of 125I-GIP to beta-cell plasma membranes from transplantable hamster insulinoma, and in stimulating insulin release from the isolated perfused rat pancreas, was investigated. Our results, in association with the results of previous studies, indicate that the sequence 17-38 is necessary for receptor binding and biological activity of GIP. By contrast, the N-terminal portion of GIP can be removed without seriously impairing the activity of the molecule.

Animals↗
PubMed1986

Gastric acid response to pentagastrin and gastrin-releasing peptide in conscious cats.

The mammalian counterpart to bombesin, gastrin-releasing peptide (GRP), is considered to stimulate gastric acid secretion by release of endogenous gastrin. The present study was carried out to examine if GRP has a stimulatory action on acid secretion in addition to that produced by released gastrin. In 4 gastric fistula (GF) and Heidenhain pouch (HP) cats, 160 pmol X kg-1 X h-1 i.v. GRP produced a GF and HP acid response that amounted to 22 and 13%, respectively, of the maximal acid response to pentagastrin, with no rise in serum gastrin concentration. GRP significantly increased the maximal acid response to pentagastrin in the GF but not in the HP. These results suggest that GRP stimulates acid secretion in cats also by an action not related to the release of gastrin. This action is greater in the presence of vagal innervation.

Animals↗
PubMed1986

Influence of beta-endorphin, somatostatin, substance P and vasoactive intestinal peptide on the proliferative response of human peripheral blood T lymphocytes to mercuric chloride.

The influence of beta-endorphin, somatostatin, substance P (SP) and vasoactive intestinal peptide (VIP) was tested on the proliferative response to mercuric chloride of human peripheral blood T lymphocytes, cultured for 5 days. When beta-endorphin, 10(-8) M, was added 1 h after mercuric chloride, there was an enhancement of the response, while a slight suppression was obtained with a 10(-6) M concentration of SP and VIP. When beta-endorphin, 10(-7)-10(-9) M, somatostatin, 10(-6)-10(-9) M, and SP, 10(-11)-10(-12) M, were added 3 days after mercuric chloride, they enhanced the response. At 10(-6) M, SP gave a suppressive effect.

Cell Division↗
PubMed1986

Modulating effect of beta-endorphin, somatostatin, substance P and vasoactive intestinal peptide on the proliferative response of peripheral blood T lymphocytes of nickel-allergic patients to nickel sulfate.

The influence of beta-endorphin, somatostatin, substance P (SP) and vasoactive intestinal peptide (VIP) was tested on the proliferative response of peripheral blood T lymphocytes of nickel-allergic subjects to nickel sulfate. With somatostatin, 10(-6)-10(-10) M, SP, 10(-9) and VIP, 10(-7)-10(-8) M, added 1 h after nickel sulfate, there was an enhancement of the response, while a slight suppression was obtained with SP, 10(-6) M. At 3 days after nickel sulfate, beta-endorphin, 10(-6)-10(-12) M, somatostatin, 10(-7)-10(-9) M and SP, 10(-7)-10(-11) M, gave an enhancement of the response.

Cells, Cultured↗
PubMed1986

The effect of galanin on canine plasma glucose and gastroenteropancreatic hormone responses to oral nutrients and intravenous arginine.

Intravenous infusion of galanin into conscious dogs during ingestion of oral glucose or a mixed meal or during iv infusion of arginine resulted in significant blunting of plasma insulin responses and significant increases in plasma glucose levels compared to those in control experiments. Galanin infusions did not significantly alter plasma gastric inhibitory peptide responses to oral glucose or a mixed meal, or plasma gastrin, pancreatic polypeptide, or pancreatic glucagon responses to a mixed meal. Similarly, galanin infusions did not significantly alter pancreatic glucagon responses to iv arginine. In all experimental situations, on cessation of the galanin infusions, prompt elevation of plasma insulin levels occurred. These results suggest that in the conscious dog, galanin administration produces a relatively selective, but readily reversible, inhibition of insulin secretion stimulated by oral nutrients or iv arginine.

Animals↗
PubMed1986

Cardiac hormones: morphology and biochemistry.

The heart contains, in addition to its myocardial working cells and the conductive system, a specialized endocrine part localized mainly in the atrial appendage which is predominantly made up by myoendocrine cells. The ultrastructural and immunocytochemical analysis of myoendocrine cells show a specialized secretory apparatus involved in the synthesis and secretion of cardiac hormones. These cardiac hormones are synthesized and processed in the myoendocrine cells as follows: a preprohormone is found in the rough endoplasmic reticulum, the prohormone cardiodilatin/gamma-atrial natriuretic polypeptide (CDD/ANP) is processed in the Golgi apparatus and stored in the secretory granules. The circulating peptide, cardiodilatin 99-126/alpha-ANP, is the C-terminus of this preprohormone which is released as the active circulating form into the blood stream.

Animals↗
PubMed1985

Isolation and characterization of proSS1-32, a peptide derived from the N-terminal region of porcine preprosomatostatin.

A peptide derived from the N-terminal region of porcine prosomatostatin, proSS1-32, has been purified to homogeneity from extracts of porcine upper intestine. Amino acid analysis revealed that the peptide consists of 32 residues. The complete primary structure was determined as: A P S D P R L R Q F L Q K S L A A A A G K Q E L A K Y F L A E L. This sequence obviously comprises residues 1-32 of porcine prosomatostatin since it is identical to the corresponding sequence in human preprosomatostatin. The postulated cleavage site in porcine prosomatostatin is a Leu-Leu bond between residues 32 and 33, thus confirming previous studies of the processing of the somatostatin precursor in the rat and transgenic mouse.

Amino Acid Sequence↗
PubMed1985

Valosin: isolation and characterization of a novel peptide from porcine intestine.

The isolation and primary structure of a novel gastrointestinal peptide, designated valosin, is described. The peptide was purified from porcine upper gut extracts using an HPLC and N-terminal sequence screening strategy which depends on chromatographic and structural characteristics as isolation criterion. The amino acid sequence of this peptide consists of 25 amino acid residues:

Amino Acid Sequence↗
PubMed1985

A proform of secretin with high secretin-like bioactivity.

A variant form of the heptacosapeptide amide secretin, with C-terminal -Val-Gly-Lys-Arg instead of valine amide, has been isolated from porcine upper intestinal tissue. Unexpectedly, this triacontapeptide exhibited a substantially higher bioactivity than the heptacosapeptide amide.

Amino Acid Sequence↗
PubMed1985

Neuropeptide K: isolation, structure and biological activities of a novel brain tachykinin.

A 36 amino acid residue peptide, which contains a substance K sequence at its C-terminus has been isolated from porcine brain extracts. The primary structure of the peptide, designated neuropeptide K (NPK), was found to be: (sequence; see text) This N-terminally extended form of substance K is present in a high concentration in the brain. The peptide is highly biologically active with regard to gallbladder contraction, protein extravasation, hypotension and bronchial smooth muscle spasm and may act as an additional tachykinin neuromessenger.

Amino Acid Sequence↗
PubMed1985

Isolation and characterization of neuropeptide Y from porcine intestine.

The isolation and primary structure of intestinal neuropeptide Y (NPY) is described. The peptide was purified from porcine intestinal extracts using a chemical assay and radioimmunoassay for NPY. The amino acid sequence of this peptide is: Tyr-Pro-Ser-Lys-Pro-Asp-Asn-Pro-Gly-Glu-Asp-Ala-Pro-Ala-Glu-Asp-Leu-Ala- Arg-Tyr-Tyr- Ser-Ala-Leu-Arg-His-Tyr-Ile-Asn-Leu-Ile-Thr-Arg-Gln-Arg-Tyr-NH2. This the structure of intestinal NPY is identical to the NPY of brain origin.

Amino Acid Sequence↗
PubMed1985

Distribution of galanin-like immunoreactivity in the gastro-intestinal tract of several mammalian species.

The distribution of galanin-immunoreactive (GAL-IR) neurons was mapped in detail in the gastro-intestinal tract of the rat, mouse, guinea-pig and pig by use of the indirect immunofluorescence technique. GAL-IR cell bodies were found in both the submucous and the myenteric plexus, with considerably higher numbers in the former ganglia. The largest number of GAL-IR perikarya was seen in the duodenal submucous plexus of the pig. With some (single) exceptions, GAL-IR cell somata were not observed in the myenteric plexus of the pig and guinea-pig, and in the submucous plexus of the esophagus and the stomach of the guinea-pig. GAL-IR fibers occurred in most parts of the gastro-intestinal tract. In the lamina propria a few non-varicose, weakly fluorescent fibers were noted in the mouse and rat, whereas in the pig and guinea-pig were large numbers of GAL-IR fibers with a varicose appearance was observed. These fibers were in all species most numerous in the distal portion of the intestinal tract. In the submucosa GAL-IR fibers were detected in all four species, and in the pig and guinea-pig some fibers surrounded blood vessels. A large number of GAL-IR fibers was generally seen in the circular smooth muscle layer, except in the guinea-pig, which only seemed to contain a few fibers. In the longitudinal muscle layer only single fibers could be detected. However, the gastric fundus region of the pig contained a moderate number of fibers in the longitudinally and obliquely oriented layers. In general, in the rat, mouse and pig, the submucous and myenteric plexus contained moderate or large numbers of GAL-IR fibers. In the guinea-pig, no or only single fibers were observed in the plexus of the upper gastro-intestinal tract and the rectum, while moderate numbers were seen in the ileum and colon. Thin adjacent sections stained for vasoactive intestinal polypeptide (VIP) and GAL revealed the coexistence of these two peptides in cell bodies of the myenteric plexus in the pig duodenum and guinea-pig colon. In these two species the GAL- and VIP-nerve fiber networks also exhibited marked similarities. However, in the rat and mouse VIP- and GAL-distribution patterns were in general different. The present findings indicate the presence of yet another neuropeptide or peptide family in the gastro-intestinal tract of several rodents and the pig.

Animals↗
PubMed1985

Cardiodilatin-immunoreactive neurons in the hypothalamus of Tupaia.

Using various region specific antibodies raised against partial sequences of synthetic cardiodilatin (CDD) we detected immunoreactive neurons with their perikarya in the nucleus periventricularis of Tupaia belangeri. The fibers could be traced laterally directed towards the amygdaloid complex and some varicosities were also observed in the lateral parts of the nucleus periventricularis. It is postulated that brain CDD represents a new neuropeptide and that these CDD-IR neurons are involved in specific functions related to the modulation of the cardiovascular centers.

Animals↗
PubMed1985

Characterization of two novel forms of cholecystokinin isolated from bovine upper intestine.

The primary structures of two novel forms of cholecystokinin, isolated from bovine upper intestine are reported. The two peptides are composed of 33 and 39 amino acid residues, respectively, the larger being an N-terminally extended form of the shorter peptide. The primary structure of the 39 amino acid peptide is: (Formula: see text) This amino acid sequence differs from the porcine hormone at positions 13 and 15, which are Val and Met, respectively, in pig, the same amino acid substitutions have previously been found to occur also in dog.

Amino Acid Sequence↗
PubMed1985

Comparative effects of vasoactive intestinal peptide and secretin on exocrine pancreatic secretion in the cat.

The stimulatory effect of vasoactive intestinal peptide (VIP) and secretin has been compared on exocrine pancreatic secretion in anaesthetized cats. Both peptides were given by bolus intravenous injection and continuous intravenous infusion. After bolus injection, VIP stimulated pancreatic secretion only weakly. On the contrary, during intravenous infusion, the maximal effect of VIP did not differ significantly from that of secretin. Therefore, while the potency of VIP is always lower than that of secretin, its efficacy appears to be strictly dependent on the mode of administration.

Animals↗
PubMed1985

Galanin inhibits insulin secretion and induces hyperglycemia in dogs.

Intravenous administration of galanin into fasted conscious dogs produced a dose-dependent hyperglycemia accompanied by decreases in plasma insulin levels, but with no elevation of plasma glucagon levels. Galanin infusions produced greater parenteral glucose-induced rises in plasma glucose levels along with markedly blunted insulin responses compared with glucose and insulin responses to control glucose infusions. Immediately after cessation of the galanin infusions, elevation of plasma insulin levels occurred in the basal state and after parenteral glucose loading. These results suggest that galanin's hyperglycemic activity is predominantly mediated by a reversible inhibition of insulin secretion.

Amino Acid Sequence↗