Differential inhibition by tedisamil (KC 8857) and glibenclamide of the responses to cromakalim and minoxidil sulphate in rat isolated aorta.

摘要: The effects of the K+ channel blockers tedisamil and glibenclamide on cromakalim- minoxidil sulphate-induced 42K+ 86Rb+ efflux vasorelaxation in rat aorta, were investigated. In aortic strips preloaded with or 86Rb+, cromakalim (1 mumol/l) induced increases tracer efflux, which concentration-dependently inhibited by similar potencies (pD2 approximately 7.3) but different amplitudes (maximum inhibition to 0% control, 10 +/- 1%). elicited a low concentration (100 nmol/l) was, however, fully tedisamil. effluxes sulphate (300 nM). Cromakalim sulphate, produced concentration-dependent noradrenaline nmol/l)-induced tone, pD2 values 7.3. Tedisamil nmol/l), greater than equal 80%, 2-fold 40-fold shifts concentration-relaxation curve for cromakalim, 3.5-fold 2200-fold respectively. Similar presence also observed when tissues precontracted potassium chloride (25 mmol/l). results show that inhibit whereas they differ greatly their ability vasorelaxant two openers.(ABSTRACT TRUNCATED AT 250 WORDS)