Vasodilative properties of BPDZ 79, a new potassium channel opener, in isolated aorta
Abstract
AIM: To compare the effect of a novel potassium channel opener
3-(1',2',2'-trimethylpropyl)amine-4H-pyrido (2,3-e)-1,2,4-thiadiazine, 1-dioxide
(BPDZ 79), with diazoxide on aorta.
METHODS: Muscle tension of rat aorta was compared with adjacent aortic rings
without endothelium. One ring was precontracted with KCl 80 mmol.L-1. Three rings
were precontracted with KCl 80 mmol.L-1, and two of them were incubated with
glibenclamide (0, 1, and 10 mumol.L-1). 86Rb outflow from rat aorta was measured
in the presence of glibenclamide 10 mumol.L-1.
RESULTS: BPDZ 79 and diazoxide provoked concentration-dependent and
endothelium-independent relaxation of the vasoconstriction evoked by KCl 30
mmol.L-1, but not by 80 mmol.L-1. BPDZ 79 showed more potent vasorelaxation and
86Rb outflow than diazoxide. After incubation with glibenclamide (1 and 10
mumol.L-1), an inhibitor of the ATP-sensitive K+ channels, the relaxation induced
by BPDZ 79 and diazoxide were decreased with the same pattern.
CONCLUSION: BPDZ 79 is a potent vasodilator by opening potassium channels.
Keywords:
3-(1',2',2'-trimethylpropyl)amine-4H-pyrido (2,3-e)-1,2,4-thiadiazine, 1-dioxide
(BPDZ 79), with diazoxide on aorta.
METHODS: Muscle tension of rat aorta was compared with adjacent aortic rings
without endothelium. One ring was precontracted with KCl 80 mmol.L-1. Three rings
were precontracted with KCl 80 mmol.L-1, and two of them were incubated with
glibenclamide (0, 1, and 10 mumol.L-1). 86Rb outflow from rat aorta was measured
in the presence of glibenclamide 10 mumol.L-1.
RESULTS: BPDZ 79 and diazoxide provoked concentration-dependent and
endothelium-independent relaxation of the vasoconstriction evoked by KCl 30
mmol.L-1, but not by 80 mmol.L-1. BPDZ 79 showed more potent vasorelaxation and
86Rb outflow than diazoxide. After incubation with glibenclamide (1 and 10
mumol.L-1), an inhibitor of the ATP-sensitive K+ channels, the relaxation induced
by BPDZ 79 and diazoxide were decreased with the same pattern.
CONCLUSION: BPDZ 79 is a potent vasodilator by opening potassium channels.