Analogous effects of zinc deficiency and aspirin toxicity in the pregnant rat.

At or near term, zinc deficient pregnant rats are depressed and exhibit difficult and extended parturition with excessive bleeding. This investigation was designed to develop objective measures of this pathology and to apply these parameters to the assessment of possible interrelationships of zinc with aldosterone and the prostaglandins. Female rats were fed during gestation a low zinc diet based on soybean protein (less than 1 ppm Zn) or the same diet supplemented with zinc (100ppm). Some of the rats were treated with aldosterone or aspirin, a prostaglandin inhibitor. Following parturition, both body temperature and blood pressure were depressed in the zinc deficient dams. Bleeding time and blood loss were also increased. Plasma potassium value were slightly elevated, adrenal weights increased and thymus weights decreased. Aldosterone had no effect on the incidence of the postpartum illness: temperature and blood pressure were unchanged. Toxic doses of aspirin produced pathologic signs analogous to those of zinc deficiency, including extended gestation period, difficult and prolonged parturition, excess bleeding, and low blood pressure and rectal temperature. The results suggest a role for zinc in prostaglandin metabolism.