The ATP‐sensitivity of K⁺ channels in rat pancreatic B‐cells is modulated by ADP

Abstract

ATP‐sensitive K + channels in inside‐out membrane patches from dispersed rat pancreatic B‐cells were studied using patch‐clamp methods. The dose‐response curve for ATP‐induced channel inhibition was shifted to higher concentrations in the presence of ADP (2 mM). In glucose‐free solution, the total intracellular concentration of ATP was 3.8 mM and of ADP 1.5 mM; glucose (20 mM) increased ATP and decreased ADP by approx. 40%. These results suggest that both ADP and ATP may be involved in regulating the activity of the glucose‐sensitive K + channel in intact B‐cells.