An attempt to prevent spontaneous hypertension in rats by antihypertensive drug treatment.

Experiments were carried out on 10 spontaneously hypertensive rats (SHR) with the intention to prevent or modify the onset and the course of spontaneous hypertension by application of a long-term antihypertensive drug treatment started during the prehypertensive period of their life. Ten untreated SHR and 10 normotensive Wistar rats (NWR) were used as controls. The results indicate that even very early administration of antihypertensive drug during the prehypertensive stage of genetically determined SH in Okamoto-Aoki rats does not suppress the onset and the development of hypertension in spite of long-term continuation. It only alters its course, suppresses the blood pressure elevation maintaining it at a "subhypertensive" level during the period of treatment, and postpones for a certain period the elevation of BP to an excessive level after medication is discontinued. It is suggested that these results should be kept in mind when prophylaxy of essential hypertension is considered.