Fig. 9.

Spermine (SPM) partially protects Kir6.2 (N160D)/SUR2A mutant channels from chloroquine (CQ) block. Top panel, patches were depolarized to +50 mV for 14 s, followed by repolarization to −80 mV. During the first trial, 10 μM spermine was applied alone during the depolarizing pulse. The experiment was repeated with 10 μM chloroquine application. In a third trial performed on the same patch, 10 μM spermine was first applied alone for 3 s, followed by application of 10 μM spermine together with 10 μM chloroquine. Bottom panel, the first second of repolarization-induced recovery of current at −80 mV is highlighted and depicts all three experimental treatments. a, recovery of spermine alone block by repolarization. b, recovery of chloroquine alone block by repolarization. c, recovery of spermine and spermine + chloroquine block by repolarization.