Inhibition by trichlormethiazide of catecholamine release from perfused bovine adrenals

Effect of thiazides on catecholamine release was examined using perfused bovine adrenal glands in vitro. Thiazides, such as trichlormethiazide and methyclothiazide inhibited catecholamine release evoked by carbamylcholine although they did not inhibit catecholamine release evoked by excess potassium. Thus it seems that these drugs inhibit catecholamine release release by an anticholinergic mechanism. Such inhibitory effect of thiazide on catecholamine release may be involved in the antihypertensive effect of these drugs.