Nitrogen metabolism in the american cockroach—I. An examination of positive nitrogen balance with respect to uric acid stores

Abstract

1. 1. Newly molted adult American cockroaches ( Periplaneta americana L.) were maintained on diets containing various concentrations of protein. Dietary nitrogen intake, body nitrogen, nitrogen uptake, uric acid storage and nitrogen elimination were monitored to examine nitrogen balance in response to maintenance on these diets. 2. 2. Adults on dog food (24% crude protein) and 24% casein protein diets increased in body nitrogen, but showed an initial decrease in uric acid nitrogen. This is suggestive of uric acid nitrogen utilization during the early post-molt period. Insects on a 5% protein diet decreased in total body and urate nitrogen. 3. 3. Cockroaches on diets containing 50, 79 and 91% casein protein showed large increases in body nitrogen which could be correlated with increased uric acid nitrogen storage. Evidence is presented that uric acid may be stored preferentially in situations where all excess dietary nitrogen is not excreted. The general metabolism of non-nitrogenous metabolic reserves may be utilized to store excess nitrogen as uric acid. 4. 4. Storage of nitrogen may involve the formation of a urate complex with protein, peptides and/or salts of urate.