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.