ATTENUATION OF THE INCREASE IN BLOOD-PRESSURE AND VASCULAR REACTIVITY BY CHRONIC ORAL-ADMINISTRATION OF SOFT-SHELLED TURTLE POWDER IN SPONTANEOUSLY HYPERTENSIVE RATS

The effects of chronic oral administration of cryomilled powder of the soft‐shelled turtle (SST powder) on blood pressure, serum catecholamine contents and vascular reactivity of spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY) were studied. The SST powder was administered orally 20–500 mg/kg/day for 9 weeks. The treatment slowly but significantly reduced the blood pressure increase in SHR. However, the SST powder did not affect the blood pressure in WKY. Heart rate and wet heart weight were not affected by the SST powder treatment. Serum content of catecholamine and aldosterone and the plasma renin activity were also unaffected by the chronic administration of the SST powder. The increase in vascular resistance of isolated mesenteric vascular beds from SHR was significantly reduced by the chronic treatment of SST powder. Vascular reactivity to norepinephrine was also smaller in the SST powder‐treated group. The treatment did not affect vascular resistance or reactivity in WKY. These results suggest that chronic oral administration of the SST powder reduces the development of hypertension by decreasing the peripheral vascular resistance and reactivity. The SST powder may be useful for the treatment of hypertension. Copyright © 1990 John Wiley & Sons, Ltd.