Further Studies on the Symptoms of Manganese Deficiency in the Rat and Mouse

Abstract

A solid basal diet has been devised which is very low in manganese and which when supplemented with this element allows much better growth than any manganese-low diet heretofore devised. Deficiency of manganese in first generation female rats started on the manganese-low diet at weaning resulted in the production of non-viable young. The deficient females were capable of raising foster stock or control young, although their own offspring died. No abnormalities were noted in the behavior of the deficient females towards their young. No disturbance in oestrous cycle due to manganese was noted in first generation females. Deficient mice likewise gave birth to non-viable young. No decrease in growth was noted in the deficient rats of the first generation on the basal diet. However, the deficient offspring, particularly the males, of stock females placed on the deficient diet late in pregnancy, were inferior in growth to littermates given manganese. Likewise, increasing the calcium and phosphorus contents of the basal diet resulted in a marked decrease in growth of first generation males. Manganese is a factor necessary for optimum growth. The deficient males were sterile. A hitherto undescribed symptom of manganese-deficiency was observed in young rats, characterized by loss of both equilibrium and coordination. The symptoms of manganese deficiency, namely, production of inferior young and poor growth of the female and sterility and poor growth of the male, are reversible by administration of manganese. A marked decrease in arginase activity of the livers of the deficient rats has been noted. The observations of various authors on the effects of manganese deficiency are discussed in connection with these results.