[Arginase activity in the liver of growing rats with manganese deficiency].

Rats weaned early at 13 days of age exhibited at 10% lower growth within 6 weeks when Mn supply was deficient compared to control animals (P is less than 0.005). While the reduction of the dietary Mn content from 50 to 6 ppm did not yet affect growth, the animals already showed a 60% lower arginase activity at this median level of Mn supply. The values of the depleted animals (0.7 ppm Mn) had fallen by 71% compared to the control group. Therefore, the arginase values may be applied to differentiate between suboptimum and optimum Mn supply.