Selective effect of high arterial pressure in hypertension upon inhibition of cGMP versus cAMP mediated vascular relaxation.

We tested the hypothesis as to whether elevated arterial pressure in hypertension alters cGMP, or cAMP, mediated vasorelaxation. Relaxation to nitroglycerin and isoproterenol was determined in isolated aortic rings from one-kidney, one clip hypertensive (1K1C), coarctation hypertensive (CH) and normotensive control (C) rats. Thoracic aortas from 1K1C and CH rats, as well as abdominal aortas from 1K1C rats, but not abdominal aortas from CH rats were exposed chronically (4-6 weeks) to elevated arterial pressure.

Noradrenergic vasorelaxation of porcine coronary arteries is enhanced by direct, acute exposure to 17 beta-estradiol.

1. We tested whether responses of isolated coronary arteries to adrenergic agents are altered by overnight (18-22 hr) or acute exposure to physiological levels of 17 beta-estradiol. 2.

Estrogen pretreatment directly potentiates endothelium-dependent vasorelaxation of porcine coronary arteries.

We tested whether vasorelaxation of coronary arteries is altered after overnight (18-22 h) exposure to physiological levels of 17 beta-estradiol. Ring segments of left circumflex coronary artery from six female and six castrated male pigs were incubated in vials of sterile Dulbecco's modified Eagle's medium with 1 nM 17 beta-estradiol, 1 nM 17 beta-estradiol + 10 nM tamoxifen, 1 nM 17 alpha-estradiol, or estrogen vehicle (ethanol) under normoxic conditions in an O2-CO2 incubator at 37 degrees C for 18-22 h. Coronary rings, with and without endothelium, were then suspended in vessel baths for measurement of isometric force.