RENIN IMMUNOCHEMISTRY, SODIUM-EXCRETION AND RELATIVE HEART-WEIGHT IN CYCLOSPORINE-INDUCED OR ALIMENTARY-INDUCED MAGNESIUM-DEFICIENCY IN RATS

Rats were given a magnesium- (Mg) depleted (Mgd), or a Mg-standard (Mg st) or a Mg-enriched (Mge) diet, with 20 mg/kg/day cyclosporine (Cy) o r olive oil per os for 90 days (6 groups). Anti-renin antibody was app lied and the percent of renin-positive glomeruli (RI) was taken. Sodiu m excretion (NaU), relative heart weight (HW), as a measure of hyperte nsion, and total femur Mg were measured. Compared to dietary controls, femur Mg was reduced under Cy and Mgd or Mgst indicating Mg deficienc y. RI was higher in all Cy groups (p < 0.01), and NaU was lower in Mgd + Cy and in Mgst + Cy (p < 0.01). Correspondingly, HW was found to be significantly higher in Mgd + Cy and Mgst + Cy. In animals under Mge + Cy, there were no differences in NaU and HW compared to controls. Th e results indicate a relation between Cy-related hypertension and Mg s tatus: Mg deficiency seems to enhance the hypertensive effect of Cy vi a sodium retention.