The effect of adrenergic agonists and antagonists on cysteine-proteinase inhibitor (cystatin) in rat saliva

The effect of a number of adrenergic agonists and antagonists on the induction of rat salivary cystatin was investigated. A highly sensitive and specific radioimmunoassay was used to determine cystatin in rat whole saliva. Treatment for 10 consecutive days with a non-specific β-adrenergic agonist isoproterenol, or the β 1-adrenergic agonists dobutamine or methoxyphenamine, resulted in the induction of the salivary cystatin. Induction was also found in rats treated for 10 days with arterenol. Only trace quantities of cystatin could be detected in saliva of rats treated with the β 2-adrenergic agonists terbutaline or salbutamol. When isoproterenol was injected concomitantly with the mixed β-antagonist propranolol or the β 1-adrenergic antagonists metaprolol, proctocol or atenolol the production of cystatin was totally suppressed. However, the β 2-antagonist, ICI 118551, produced only a partial reduction in salivary cystatin induction elicited by isoproterenol. The findings suggest that the induction of salivary cystatin is regulated, in part, by β 1-adrenergic receptor stimulation.