Insulin-induced endothelin release and vasoreactivity in hypertriglyceridemic and hypertensive rats.
Insulin-elicited endothelin release in hypertriglyceridemic, hypertensive, hyperinsulinemic (HTG) rats was shown. Weanling male Wistar rats were given 30% sucrose in their drinking water for 20-24 wk. In vitro contractions of aorta and femoral arteries were elicited with 40 mM KCl. Endothelin release induced with KCl plus 50 microU/ml insulin resulted in increases in contractile responses: 41 +/- 5.9 and 57 +/- 6% for control and 65.5 +/- 6 and 95 +/- 9% for HTG aortas and femoral arteries, respectively. The endothelin ET(B)-receptor blocker BQ-788 decreased responses to KCl + insulin by 39 +/- 8 and 53 +/- 5% in control and 48 +/- 13 and 79 +/- 3.5% in HTG aortas and femoral arteries, respectively. The ET(A)-receptor antagonist PD-151242 inhibited these responses by 12 +/- 10 and 1 +/- 9% in control and by 51.5 +/- 9 and 58.5 +/- 1% in HTG aortas and femoral arteries, respectively. These results suggest that endothelin may contribute to the hypertension in this model.
Department of Physiology, Instituto Nacional de Cardiología "Ignacio Chávez," Mexico City, DF 14080, Mexico.
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D000818:Animals; D000831:Animals, Newborn; D000959:Antihypertensive Agents / Q000494:pharmacology; D001381:Azepines / Q000494:pharmacology; D019332:Endothelin-1 / Q000378:metabolism*; D005951:Glucose Tolerance Test; D006973:Hypertension / Q000378:metabolism / Q000503:physiopathology*; D015228:Hypertriglyceridemia / Q000378:metabolism / Q000503:physiopathology*; D007328:Insulin / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000503:physiopathology; D009842:Oligopeptides / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
D000959:Antihypertensive Agents; D001381:Azepines; D019332:Endothelin-1; D007328:Insulin; D009842:Oligopeptides; D010880:Piperidines; C087850:PD 151242; C086539:BQ 788; D011189:Potassium Chloride