Simultaneous measurement of plasma protein extravasation and carotid vascular resistance in the rat.

Stimulation of the right trigeminal ganglion in pentobarbital anaesthetised rats increased mean arterial blood pressure and decreased right carotid vascular resistance but had no effect on left carotid vascular resistance. Sumatriptan (0.3 mg/kg i.

Endothelin in the gastrointestinal tract. Presence of endothelinlike immunoreactivity, endothelin-1 messenger RNA, endothelin receptors, and pharmacological effect.

The possible production and role of endothelin in the gastrointestinal tract was investigated in rats by radioimmunoassay, Northern-blot hybridization, receptor assay using membrane preparations, and pharmacological study using gut strips. Endothelinlike immunoreactivity was detected in all regions (from stomach to colon) of the rat gastrointestinal tract (13-48 fmol/g wet tissue) including the mucosal layer of the ileum and colon (8.4 +/- 2.

Comparison of neuromedin-N and neurotensin on net fluid flux across rat small intestine.

Neuromedin-N, a hexapeptide recently isolated and purified from porcine spinal cord, has close sequence homology with the C-terminal region of the tridecapeptide neurotensin. Both peptides have a remarkably similar peripheral distribution. Little is known of the biological activity of neuromedin-N.

Increased pressor effect of repeated doses of rat or porcine endothelin in the anaesthetised rat.

Rat and porcine endothelin differ by 6 amino acids. Porcine and rat endothelin were equiactive at producing the transient fall in blood pressure in the anaesthetised rat but porcine endothelin was three times more potent at producing the subsequent sustained rise. Repeated doses of either peptide in the same rat produced a larger pressor response with each repetition, the peak response being reached more rapidly.

The distribution, purification, and pharmacological action of an amphibian neuromedin U.

The distribution, primary structure, and relative biological activity of neuromedin U has been determined from the frog Rana temporaria. Following sequential column chromatography of a gastrointestinal extract, the peptide was sufficiently pure to enable characterization by micro-sequence analysis. The entire sequence was found to be an icosapentapeptide which displays marked sequence similarity to both porcine and rat neuromedin U.

Effects of prepro-vasoactive intestinal polypeptide-derived peptides on net fluid flux in small intestine of anesthetized rats.

Intravenous infusion of low doses of vasoactive intestinal polypeptide, peptide histidine valine-42, and peptide histidine methionine (and the rat equivalent, peptide histidine isoleucine) into anesthetized rats caused a reduction in net absorption of fluid from the small intestine. Larger doses caused a net fluid secretion. At the same nominal infusion rates, peptide histidine valine-42 appeared to be the most potent.

Studies with endothelin-3 and endothelin-1 on rat blood pressure and isolated tissues: evidence for multiple endothelin receptor subtypes.

In an anesthetized rat, endothelin-1 (ET-1) causes a rapid, transient fall in blood pressure followed by a large, sustained rise. Rat endothelin-3 (ET-3) differs from porcine endothelin-1 (ET-1) by six amino acids and is 20 times less potent at contracting rat aortic strips. The comparative effects of ET-3 and ET-1 on blood pressure were studied in anesthetized rats in which the arterial blood pressure was continually monitored.

Differential expression of alpha-CGRP and beta-CGRP by primary sensory neurons and enteric autonomic neurons of the rat.

Expression of the calcitonin gene-related peptide, alpha-calcitonin gene-related peptide (CGRP), and the homologous beta-CGRP were compared in sensory and enteric nerves of the rat. Analysis of CGRP-like immunoreactivity by cation exchange chromatography and radioimmunoassay showed that in the dorsal root ganglia, dorsal spinal cord and in those peripheral tissues where CGRP-like immunoreactivity is primarily localized to sensory fibres, alpha-CGRP concentrations were three to six times greater than beta-CGRP concentrations. In the intestine, however, beta-CGRP concentrations were up to seven times greater than alpha-CGRP concentrations.

Isolation, characterization, and pharmacological actions of peptide histidine valine 42, a novel prepro-vasoactive intestinal peptide-derived peptide.

The primary structure and biological activity of a novel prepro-vasoactive intestinal peptide (prepro-VIP)-derived peptide has been determined from an adrenal pheochromocytoma. The peptide was purified sufficiently for characterization by fast atom bombardment mapping after cation-exchange and reverse-phase fast protein liquid chromatography. The sequence of this novel peptide corresponds exactly to prepro-VIP-81-122 and has been designated peptide histidine valine 42 (PHV-42).

Basilar artery dissection.

Dissection of the basilar artery caused sudden coma and death in a 40-year-old man. Atypical clinical features were explained at necropsy. A ventral dissection of the artery within its outer layers resulted in destruction of the pontine tegmentum with sparing of the basis pontis.