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.
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Department of Physiology, Instituto Nacional de Cardiología "Ignacio Chávez," Mexico City, DF 14080, Mexico.
Guarner
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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