Methyclothiazide attenuates salt-induced hypertension without affecting sympathetic responsiveness in Dahl rats

Methyclothiazide added for 7 weeks to the drinking water of weanling Dahl rats attenuated development of hypertension in salt-sensitive (DS) rats, but did not affect blood pressure in salt-resistant (DR) ones. There were no appreciable effects on heart rate, body weight, or sympathetic nerve activity. Cardiovascular responses to electrical stimulation of the ventromedial hypothalamus, or to intravenous injections of norepinephrine, tyramine, or vasopressin, were likewise unaffected. These results indicate that the antihypertensive effect of methyclothiazide in DS rats does not depend on sympathetic inhibition.