Effects of the K+ channel activators, RP 52891, cromakalim and diazoxide, on the plasma insulin level, plasma renin activity and blood pressure in rats.

In normo- or hyperglycemic (i.v. infusion of 50 mg/kg/min glucose over 30 min) pithed rats, diazoxide (1 mg/kg/min i.

Longitudinal study of solute excretion and glomerular ultrastructure in an experimental model of aging rats free of kidney disease.

Because experimental studies of kidney aging are frequently complicated by the presence of renal disease, we set out to define a model minimizing renal pathology and thus revealing basic aging phenomena. Male and female Wistar/Lou rats were conceived, born, and bred to 42 months in a specific pathogen-free husbandry. They had free access to water and to a protein diet containing 2% fish and 15% vegetable proteins.

K+ channel opening mediates the vasorelaxant effects of nicorandil in the intact vascular system.

Nicorandil and cromakalim relaxed rat aortic rings denuded of endothelium and precontracted with a low concentration of KCl (25 mM). Glibenclamide (1 microM) strongly antagonized only the effects of cromakalim while those of nicorandil were inhibited by methylene blue, an inhibitor of the soluble form of guanylate cyclase. High concentrations of nicorandil also produced vasorelaxation in aortic preparations contracted with 55 mM KCl, whereas cromakalim did not.

Cardiovascular and biological effects of K+ channel openers, a class of drugs with vasorelaxant and cardioprotective properties.

Several new chemical entities (RP 52891, cromakalim and its derivatives) are potent and specific openers of vascular K+ channels. This mechanism is also shared, at least partially, by drugs such as minoxidil, diazoxide, pinacidil and nicorandil. The opening of plasmalemma K+ channels produces loss of cytosolic K+.

Increase in plasma renin activity evoked by fenoldopam in dogs is directly mediated by dopamine1 receptor stimulation.

In anesthetized dogs, a 15-min intravenous (i.v.) infusion of fenoldopam (2.