Long term treatment with clonidine during the development of hypertension in spontaneously hypertensive rats

Chronic administration of clonidine in the drinking water of spontaneously hypertensive (SH) rats from 11 through 17 weeks of age prevented the further development of hypertension in this model. A dosage adjustment (from about 0.1 to 0.5 mg/kg) was required to maintain a stable systolic pressure of about 200 mmHg. After six weeks of treatment clonidine was withheld for 48 hrs during which time blood pressure increased to a level similar to that of untreated controls.