Effects of glyburide on renal tubule transport and potassium-channel activity.

Renal clearance, microperfusion and patch-clamp techniques were used to investigate the effects of the K-channel blocker glyburide on electrolyte excretion, the transport properties of the thick ascending limb (TAL) of Henle and K-channel activity in the apical membrane of the TAL and of the cortical collecting tubule. Our data suggest that the K-channel blocker glyburide can inhibit transport of Na and K in the TAL by blocking K recycling across the apical membrane. Additionally, inhibition of K secretion in the collecting ducts occurs by decreasing the activity of apical K channels and prevents kaliuresis.