Studies on salivary flow in borderline hypertension.

Salivary flow and the influence of drugs on this variable were studied in subjects with borderline hypertension and in normotensive control subjects. Saliva production under resting conditions was 0.85 +/- 0.08 g/min in normotensive subjects and 0.51 +/- 0.04 g/min in borderline hypertensive subjects. In both groups of subjects studied, salivary secretion was decreased by atropine but propranolol and phentolamine had no effect. The stimulating effect of neostigmine on saliva production was more pronounced in normotensive than in borderline hypertensive subjects. Thus, in order to increase salivary flow by 1 g/min 28 +/- 0.9 micrograms/min neostigmine had to be infused intravenously in normotensives compared with 41 +/- 3.8 micrograms/min in borderline hypertensives. The results of the study suggest that subjects with borderline hypertension have a reduced parasympathetic drive to the salivary glands.