The effect of a selective inhibition of potassium channels on the relaxation induced by nitric oxide in the human pregnant myometrium.

The aim of this study was to investigate whether apamin-sensitive K(+)channels play a role in the NO induced relaxation of the human pregnant myometrium. Concentration-response curves for sodium nitroprusside (SNP) (10(-9)-10(-4)M) were constructed in the absence and presence of 10(-8)M apamin and 10(-7)M charybdotoxin (CTX). Preincubation with apamin resulted in a significant attenuation of the relaxation caused by SNP, while pre-treatment with CTX insignificantly decreased the SNP induced relaxation. Our findings suggest that apamin-sensitive K(+)channels exist in the human pregnant myometrium and play a role in modulation of the myometrium response to NO donors