Food restriction reduces the blood pressure of the spontaneously hypertensive rat

Spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto (WKy) and Sprague-Dawley (S-D) rats were fed a normal diet on an $\text{ad}$$\text{libitum}$ basis or the normal diet was reduced by 35 per cent prior to, during, and after high blood pressure became established in SHR. Weight loss occurred in all animals at all ages and was associated with effective inhibition of the acute rise in blood pressure and the exacerbation of pre-existing elevated blood pressure. Weight loss after high blood pressure had become well established also caused reduction in blood pressure. The purported normotensive WKy rats developed high blood pressure. Weight loss was not as effective in reducing blood pressure in WKy as in SHR. These findings are construed to mean that reduced body weight will ameliorate the inexorable rise in the genetically-programmed high blood pressure of SHR if instituted prior to, during, but not after high blood pressure has become well established.