Insulin-like growth factor-1 (IGF-1) inhibits the basolateral Cl channels in the thick ascending limb of the rat kidney

►The patch-clamp experiments were performed in the thick ascending limb (TAL). ►Application of 200 nM IGF-1 inhibited the basolateral Cl channels in the TAL. ►The basolateral Cl channel is a rate limiting step for Cl exit in the TAL cells. ►Rising intracellular Cl level leads to inhibition of trans-cellular Cl transport. ►IGF-1 at high concentration may inhibit epithelial transport in the TAL.