PubMed Health⌕ Search

Biomedical subjects

V Mutt

Publications and source records attributed to V Mutt.

At least 91 records · Page 5Linked to original sources
PubMed1984

Isolation and characterization of cholecystokinin-58 (CCK-58) from porcine brain.

A 58-residue peptide has been isolated from extracts of porcine brain and shown to be an N-terminally extended cholecystokinin (CCK). The amino acid sequence of this peptide is: Ala-Val-Gln-Lys-Val-Asp-Gly-Glu-Ser-Arg-Ala-His-Leu-Gly-Ala-Leu-Leu-Ala- Arg-Tyr- Ile-Gln-Gln-Ala-Arg-Lys-Ala-Pro-Ser-Gly-Arg-Val-Ser-Met-Ile-Lys-Asn-Leu- Gln-Ser- Leu-Asp-Pro-Ser-His-Arg-Ile-Ser-Asp-Arg-Asp-Tyr(SO3)-Met-Gly-Trp-Met-Asp -Phe-NH2. The peptide was found to induce contraction of the guinea-pig gallbladder, but the pattern of this action seemed to differ from those of CCK-8 and CCK-33.

Amino Acid Sequence↗
PubMed1984

A galanin-like peptide in the central nervous system and intestine of the rat.

Galanin (GAL), a 29 amino acid peptide, was recently isolated from the small intestine of pigs. In the present study an antiserum towards porcine GAL has been developed and used for radioimmunoassay and immunohistochemical studies. We now report that GAL-like immunoreactivity occurs in wide-spread systems in the rat CNS and intestine.

Animals↗
PubMed1984

A C-terminal fragment of hemoglobin beta-chains in extracts of porcine upper intestine.

A 32-residue peptide has been isolated from extracts of porcine upper intestine. Amino acid sequence determination showed that the peptide is a fragment of hemoglobin, corresponding to the C-terminal part of the beta-chain. The region in the beta-chain which precedes the isolated fragment is hydrophobic (8 Leu/Val/Ile) and has no charges at 10 preceding positions. It therefore, to some extent, resembles the structure of 'signal sequences' which may suggest a specific cleavage site in hemoglobin beta-chains.

Amino Acid Sequence↗
PubMed1984

Immunohistochemical localization of cardiodilatin in myoendocrine cells of the cardiac atria.

Region-specific antibodies against synthetic N-terminal fragments of cardiodilatin (CDD) were raised in rabbits and used for the immunohistochemical detection of this new peptide hormone in the myoendocrine cells within the cardiac atria of several species. The peroxidase-antiperoxidase (PAP) and fluorescein isothiocyanate (FITC) immunohistochemical methods gave identical results of cardiodilatin-immunoreactivity (CDD-IR) within the tissue. In addition to the porcine right atrial appendage, myoendocrine cells with CDD-IR were also detected in the left atrium of porcine heart, as well as in other species such as dog and cat. The exact localization of the immunoreactivity in specific secretory granules was mostly related to the Golgi-area which is located on both nuclear poles of auricular myoendocrine cells. The results confirm that cardiodilatin is stored in secretory granules observed through electron microscopical means. This hormone is most likely synthesized and released in myoendocrine cells, exerting its important cardiovascular effects.

Animals↗
PubMed1984

Secretin, VIP, and PHI stimulate rat proximal duodenal surface epithelial bicarbonate secretion in vivo.

The surface epithelial cells of the stomach and duodenum secrete bicarbonate at rest and in response to a number of agonists including the gastrointestinal hormones, glucagon, and GIP. Since those hormones with structural homology may have similar effects, the purpose of the present study was to examine the effect of graded doses (6, 24, and 96 nmol/kg) of pure porcine secretin, VIP, and PHI on bicarbonate secretion by the proximal duodenum containing Brunner's glands. Experiments were performed in vivo on unanesthetized Sprague-Dawley rats with chronic Thiry-Vella type loops of the proximal 2 cm of duodenum. The order of testing was random and only one hormone was tested on a single day. Compared to the saline control, each dose of VIP produced a significant increase in duodenal bicarbonate secretion in a dose-response manner. The two higher doses of secretin and only the 96 nmol/kg dose of PHI significantly increased bicarbonate output. The responses to 96 nmol/kg dose of secretin and VIP were similar, and each was significantly greater than observed with PHI. It is concluded that secretin and VIP stimulate proximal duodenal bicarbonate secretion and are more potent than PHI.

Animals↗
PubMed1984

Differential co-existence of neuropeptide Y (NPY)-like immunoreactivity with catecholamines in the central nervous system of the rat.

The distribution of neuropeptide Y immunoreactive cell bodies in relation to various types of catecholamine-containing cell bodies in the rat brain was analyzed immunohistochemically using antisera to tyrosine hydroxylase, dopamine beta-hydroxylase and phenylethanolamine N-methyltransferase. Coexistence of the peptide in catecholamine cell bodies was established by using an elution-restaining procedure. Neuropeptide Y-like immunoreactivity was observed in most noradrenergic cell bodies of the Al/Cl cell groups in the ventro lateral medulla oblongata. Similarly this peptide immunoreactivity was also observed in the majority of the adrenergic cell bodies of the C2 group. In the dorsal and dorsal-lateral part of the nucleus of the solitary tract, where a group of small adrenergic cells is present, several small neuropeptide Y immunoreactive cells were also observed. The possibility of coexistence of adrenaline and neuropeptide Y in these cells remains to be established. The majority of the noradrenergic cell bodies of the A2 group, as well as the presumptive dopaminergic cells within its ventromedial part, seemed to lack neuropeptide Y-like immunoreactivity. Many noradrenergic cell bodies of the A6 group in the locus coeruleus proper were neuropeptide Y-immunoreactive, whereas the peptide could not be observed in the subcoeruleus group. Neither the A5 and A7 noradrenergic cells in the pons, nor any of the dopaminergic cell groups in the mesencephalon and forebrain (A8-A15) seemed to contain a neuropeptide Y-like peptide. The findings indicate that central catecholamine neurons can be subdivided into distinct sub-groups based upon the coexistence of a specific peptide.

Animals↗
PubMed1984

Actions of centrally administered neuropeptide Y on EEG activity in different rat strains and in different phases of their circadian cycle.

The effects of centrally administered neuropeptide Y (NPY) on the sleep-wakefulness cycle have been studied by analyzing its action in different strains of rats with or without spontaneous hypertension and during two different phases of the circadian cycle. Normal adult Sprague-Dawley (SD), Wistar-Kyoto (WKy) and spontaneous hypertensive (SH) rats were used. By means of EEG electrodes the recording of the fronto-parietal electrocorticogram and the electromyogram could be made. Stainless steel cannula were also implanted into the lateral ventricle. The effects of an intraventricular injection of NPY (1.25 nmol/rat) was compared with the effects of the vehicle (saline) alone. The EEG patterns were classified as desynchronized, mixed or synchronized. In the SD rats NPY produced behavioural signs of sedation and a significant reduction of synchronized EEG activity as well as significant increase of synchronized and mixed EEG activities in comparison with the saline treated rats. In the WKy rats NPY administration produced an increase of synchronized EEG activity during evening sessions. In SH rats NPY produced a significant increase of desynchronized EEG activity and a decrease in mixed EEG activity indicating an awakening effect of the peptide. In view of the NPY innervation of the locus ceruleus, it therefore seems possible that the neuronal and hormonal regulation of the locus ceruleus noradrenaline nerve cells is different in the two strains of rats. It also seems possible that the ability of NPY to increase wakefulness in hypertensive animals is related to abnormal changes in the alpha 2-adrenoreceptors taking place in SH rats.

Animals↗
PubMed1984

Effect of peptide histidine isoleucine on water and electrolyte transport in the human jejunum.

Peptide histidine isoleucine, a 27 amino acid peptide with close amino acid sequence homology to vasoactive intestinal peptide and secretin, is distributed throughout the mammalian intestinal tract, where it has been localised to intramural neurones. An intestinal perfusion technique has been used to study the effect of intravenous peptide histidine isoleucine (44.5 pmol/kg/min) on water and electrolyte transport from a plasma like electrolyte solution in human jejunum in vivo. Peptide histidine isoleucine infusion produced peak plasma peptide histidine isoleucine concentrations in the range 2000-3000 pmol/l, flushing, tachycardia and a reduction in diastolic blood pressure. Peptide histidine isoleucine caused a significant inhibition of net absorption of water, sodium, potassium and bicarbonate and induced a net secretion of chloride, these changes being completely reversed during the post-peptide histidine isoleucine period. These findings suggest that endogenous peptide histidine isoleucine may participate in the neurohumoral regulation of water and electrolyte transport in the human jejunum.

Adult↗
PubMed1984

Evidence for the presence of a neutral insulinotrophic peptide in the porcine duodenum.

A crude mixture of thermostable peptides extracted from porcine duodenum was fractionated by electrofocusing. A neutral fraction, different from the basic fractions of GIP, VIP, PHI, and CCK was found to promote insulin secretion when injected in vivo to normal rats. This neutral fraction, extracted from the crude mixture by chromatography, stimulated insulin output from an isolated rat pancreas and enhanced glucose-induced insulin release. The insulinotrophic effect of this partially purified duodeno-jejunal material disappeared following digestion with trypsin. The insulin-releasing activity was found to correspond to a compound of molecular weight higher than that of insulin (i.e. higher than 6000). No GIP-like immunoreactivity was found in this neutral fraction indicating that the active peptide(s) are not GIP related compounds. These observations suggest that porcine duodenum contains and incretin activity different from that of the insulinotrophic factors already reported.

Animals↗
PubMed1983

Galanin - a novel biologically active peptide from porcine intestine.

The isolation of a novel biologically active peptide, designated galanin, is described. The peptide was discovered by the detection of its C-terminal amide structure in porcine intestinal extract using a chemical method. It was found that galanin consists of 29 amino acids and the complete amino acid sequence is: Gly-Trp-Thr-Leu-Asn-Ser-Ala-Gly-Tyr-Leu-Leu-Gly-Pro-His-Ala-Ile-Asp-Asn-His -Arg-Ser -Phe-His-Asp-Lys-Tyr-Gly-Leu-Ala-NH2. Galanin was found to contract smooth muscle preparations from the rat and to cause a mild and sustained hyperglycemia in dog.

Amino Acid Sequence↗
PubMed1983

Identification and characterization of variant forms of the gastrin-releasing peptide (GRP).

Porcine intestinal gastrin-releasing peptide (GRP) has been demonstrated to be structurally identical to the previously characterized gastric GRP. Ion-exchange and high-performance liquid chromatography of porcine intestinal extracts have identified two variant GRP forms. Studies on one of these variant forms suggest that a beta-aspartyl shift has occurred in the Asn-His structure of GRP; such a modification in an Asn-His structure occurring in a natural peptide or protein has not been previously reported. This variant GRP, although retaining bioactivity, appears to have reduced potency in elevating canine plasma gastrin levels.

Amino Acid Sequence↗
PubMed1983

Immunohistochemical indications of gastrin releasing peptide--bombesin-like immunoreactivity in the nervous system of the rat. Codistribution with substance P-like immunoreactive nerve terminal systems and coexistence with substance P-like immunoreactivity in dorsal root ganglion cell bodies.

Weak to strong gastrin releasing peptide--bombesin (GRP-Bn)-like immunoreactivity was found in fine varicose nerve terminal systems of low to high densities in several parts of the CNS. The highest densities of strongly immunoreactive terminals were found in the marginal layer and in the substantia gelatinosa of the spinal cord, and in parts of the nuc. tractus spinalis nervi trigemini. Morphometrical analysis in the spinal cord demonstrates that GRP-BN-like-immunoreactive and substance P (SP), but not somatostatin (SS)-immunoreactive nerve terminals strikingly codistribute. Coexistence of SP and GRP-BN-like immunoreactivities was demonstrated in trigeminal and spinal ganglion nerve cells. Thus, GRP-BN-like immunoreactivity may coexist with SP in certain SP-immunoreactive nerve terminal systems.

Animals↗
PubMed1983

Isolation of a brain peptide identical to the intestinal PHI (peptide HI).

The isolation of a brain peptide identical to the intestinal peptide PHI (peptide HI) is described. The peptide was isolated from porcine brain extract using a chemical assay method based on its C-terminal isoleucine amide structure. The complete amino acid sequence of the peptide was found to be: His-Ala-Asp-Gly-Val-Phe-Thr-Ser-Asp-Phe-Ser-Arg-Leu-Leu-Gly-Gln-Leu-Ser-Ala- Lys-Lys-Tyr-Leu-Glu-Ser-Leu-Ile-NH2. This sequence is identical to the intestinal peptide thus demonstrating PHI to be a brain-gut peptide. The role of PHI in the central nervous system as a neurotransmitter or neuromodulator is discussed.

Amino Acid Sequence↗