PREVENTIVE EFFECTS OF SHICHIMOTSU-KOKA-TO ON RENAL LESIONS IN STROKE-PRONE SPONTANEOUSLY HYPERTENSIVE RATS

Shichimotsu-koka-to (SKT) has been prescribed to treat patients with e ssential and renal hypertension. We investigated the effects of SKT on renal lesions in stroke-prone spontaneously hypertensive rats (SHRSPs ). SHRSPs were given an extract of SKT by mixing it with drinking wate r, from 8 through 29 weeks of age, so that the average intake of SKT e xtract was about 1.5 g/kg/d, At 29 weeks of age, the kidneys of SHRSPs exhibited proliferative arteritis characterized by the proliferation of smooth muscle cells in the interlobular arteries, dilation and dege neration of renal tubules, infiltration of inflammatory cells and hemo rrhage, with partial swelling or necrotizing of glomeruli, In particul ar, arteritis and periarteritis were noted. The treatment of SHRSPs wi th SKT ameliorated this morphological damage in the kidney and signifi cantly decreased urea nitrogen in the serum. Treatment with SKT also s trongly decreased the xanthine oxidase (XOD) activity and significantl y increased the superoxide dismutase (SOD) activity in the kidney of S HRSPs; consequently, these values became close to those in normotensiv e Wistar Kyoto rats (WKYs). These results indicate that treatment with SKT ameliorated the histopathological damage and change in activity o f enzymes related to free radicals in the kidney of SHRSPs, which may be important mechanisms for SKT for protecting SHRSPs from renal dysfu nction.