Sotalol potentiates the leukotriene C4-induced contractions and thromboxane A2 release of guinea pig lung parenchymal strips.

The leukotriene C4 (LTC4)-induced contraction and thromboxane A2 (TxA2) release of the guinea pig lung parenchymal (GPLP) strip are both inhibited by the beta 2-adrenergic agent salbutamol. The effect of LTC4 is restored to nearly normal by the beta-adrenergic antagonist sotalol. The latter substance alone also induces a contraction in the GPLP strip and potentiates the contractions and the TxA2 release of LTC4. During the sotalol-induced contractions, no TxA2 release occurs. An antihistaminic, mepyramine had no effect on the sotalol-induced contraction. When sotalol is added repeatedly to a GPLP strip, only the first time a contraction occurs.