Regional vasodilator actions of calcitonin gene-related peptide in conscious SHR.
In the present study the regional hemodynamic effects of CGRP were examined in conscious unrestrained spontaneously hypertensive rats (SHR). The animals were chronically instrumented with miniaturized pulsed Doppler flow probes to allow continuous measurement of renal, mesenteric and hindquarter blood flow. Bolus intravenous injection of CGRP (0.1-5 micrograms/kg) produced a dose-dependent fall in mean arterial pressure (maximal change = -48 +/- 5 mmHg) which was accompanied by a marked tachycardia (maximal change = 143 +/- 16 b/min). Depressor responses to CGRP were sustained for approximately 3-5 min. CGRP markedly reduced regional vascular resistance in all three vascular beds. No regional-selective vasodilator response was observed. These data indicate that CGRP is a potent vasodilator peptide in conscious SHR. The study suggests further that CGRP may contribute to the physiologic regulation of cardiovascular function.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D015740:Calcitonin Gene-Related Peptide; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D009479:Neuropeptides / Q000494:pharmacology*; D051381:Rats; D011918:Rats, Inbred SHR; D012039:Regional Blood Flow / Q000187:drug effects; D012079:Renal Circulation / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*
D009479:Neuropeptides; D015740:Calcitonin Gene-Related Peptide