Regulation of parotid kallikrein secretion-role of the alpha 2- and beta-adrenergic system.

The effects of pharmacologically induced alterations of alpha 1, alpha 2 and beta-adrenergic system on kallikrein secretion - measured as amidolytic activity - in rat parotid gland were tested in vivo. Beta and alpha 1/2-adrenergic stimulation (Orciprenaline, alpha-methylnorepinephrine) caused a comparably significant increase of parotid kallikrein secretion. Alpha 2-receptor blockade (yohimbine) but not the alpha 1-antagonist prazosin, partly abolished the effect of alpha-methylnorepinephrine. The effects of the alpha 1-adreno-receptor agonist norfenephrine on kallikrein secretion were significantly lower compared to alpha 1/2-adreno-receptor-stimulation.