Studies of salivary flow in borderline hypertension: effects of drugs acting on structures innervated by the autonomic nervous system.

Salivary flow and the influence of drugs on this were studied in subjects with borderline hypertension and in normotensive subjects. Saliva production at rest was lower in borderline hypertensive subjects than in normotensive subjects. Plasma catecholamine levels were similar in both groups of subjects studied. Intravenous injections of propranolol and phentolamine did not enhance saliva secretion in the borderline hypertensive group, whereas atropine caused the secretion to decrease in both groups. Intravenous infusions of neostigmine led to a dose-dependent increase of salivary flow. The dose-response curve for the stimulating effect of neostigmine on saliva production was shifted to the right in borderline hypertensive as compared with normotensive subjects. The results of the study support the assumption that in subjects with borderline hypertension parasympathetic influence on the salivary glands is reduced.