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Biomedical subjects

K G Braslis

Publications and source records attributed to K G Braslis.

20 records · Page 2Linked to original sources
PubMed1988

The cardiovascular effects of human calcitonin gene-related peptide in conscious sheep.

Calcitonin gene-related peptide (CGRP) is localized in nerve fibres in close association with the vasculature. The in vivo effect of human CGRP upon the cardiovascular system was investigated by intravenous infusion of CGRP into seven conscious sheep at doses of 1.5 and 10-pmol/kg per min for 75 min. CGRP at the 5- and 10-pmol/kg per min infusions decreased mean arterial pressure (maximal decrease of 10 mmHg) and stroke volume (maximal decrease of 42 ml/min), and increased heart rate by 60 beats/min. No changes in cardiac output were observed and total peripheral resistance only fell with the 5-pmol/kg per min infusion. Increases in both plasma arginine vasopressin and plasma renin concentration and a decrease in total and ionized plasma calcium were also observed. CGRP appears to be a potent vasodilator acting upon both arterioles and capacitance vessels in vivo.

Animals↗
PubMed1988

Pharmacokinetics and organ-specific metabolism of calcitonin gene-related peptide in sheep.

Calcitonin gene-related peptide (CGRP) is a product of the calcitonin gene with a widespread distribution in neural tissue of the brain, gut and perivascular nerves. Infusion of CGRP produces multiple biological effects, but the physiological significance of these findings will be influenced by the sites and rates of CGRP metabolism. The metabolic clearance rate and half-life of disappearance of human CGRP were estimated in conscious sheep after infusing CGRP at 1 or 5 pmol/kg per min to steady-state conditions. The particular organs involved in the clearance of CGRP were assessed by measuring the inflow and outflow concentrations across the liver, gut, kidney, lung and brain. The metabolic clearance rate at steady state was 22.6 +/- 2.1 (S.E.M.) and 15.0 +/- 17 ml/kg per min for the 1 and 5 pmol/kg per min doses respectively. The half-life of disappearance was bi-exponential: 3.6 +/- 0.3 min for the first phase and 13.6 +/- 1.0 min for the second phase. High-pressure liquid chromatography of plasma at equilibrium revealed only a single peak coeluting with CGRP(1-37): no immunoreactive metabolites were detected. These pharmacokinetic values are intermediate between that of a neurotransmitter and a hormone and are therefore consistent for a peptide with both circulatory and neurotransmitter modes of action. The kidney, with an arterial-renal vein gradient of 14%, and the liver, with a portal-hepatic vein gradient of 25%, were the major organs involved in the clearance of CGRP.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗