Expression of K channels in Xenopus laevis oocytes injected with poly(A+) mRNA from the insulin-secreting beta-cell line, HIT T15.

Two types of exogenous K channel were identified in Xenopus laevis oocytes injected with poly(A+) mRNA from the insulin-secreting cell line HIT T15. One of these was the ATP-regulated K channel (G channel) as evidenced by its conductance and inhibition by tolbutamide. The other resembled the Ca-activated K channel from beta-cells.