Conjugation and Excretion of Aromatic Acids in Cockroaches

Abstract

(1) The metabolism of p-aminobenzoic acid and p—aminobenzoylglycine has been examined in the American cockroach, Periplaneta americana. Glycine and glucoside conjugates were the major metabolites of p-aminobenzoic acid. Dosed p-aminobenzoylglycine was rapidly hydrolysed to the free acid by intact animals and in body extracts. (2) Extracts of excreta contained mainly the free acid with small amounts of glycine and glucoside conjugates. Larger amounts of conjugates were present in body extracts. (3) Cockroaches showed variable behaviour in excretion patterns but sex differences did not apparently affect the excretion of dose. Factors affecting excretion include temperature and feeding. (4) The distribution of dose is closely linked to the rate of excretion. Most cockroaches excreted more than half the dose within 7 days. Poor excretors retained the bulk of the dose in the carcass and gut. (5) Approximately 20% of the dose was found in the haemo-lymph 15 minutes after dosing. The bulk of the dose was initially localised in the carcass. Gut and carcass served as temporary storage sites. A model of dose distribution has been postulated.