RESUMO
Mercapturic acids (MA) are a group of compounds produced during detoxification processes in vivo. The extent to which a cell is exposed to toxic substances is therefore reflected by increased urinary. MA output. Toxins are effectively neutralised by the formation of a conjugate with glutathione (GSH); this reaction is catalysed by glutathione s-transferase (GST). Severely malnourished children have poorly functioning antioxidant systems and are often exposed to increased oxidant stress; their detoxification systems are probably being overworked. This is supported by our previous finding that erythrocyte GST activity is induced in malnourished children. As MA are the end product of GST activity, we reasoned that hte urinary MA output should also be elevated. This may assist in explaining the low level of GSH foun in children with oedematous malnutrition and provide a quantitative measure of the total body load of exogenous and endogenous carbony-like toxins. Twenty -four-hour urinary output of MA and creatinine were measured in 19 severely malnourished children, on admission and at discharge. Three healthy children served as controls. The results are as follows: MA (æmol/kg child) Control - 1.2ñ0.1, Malnour - 4.2ñ0.6, Maras. - 3.4ñ0.8, Mar/Kwash. - 5.1ñ1.2, Kwash. 4.4ñ1.1 . MA (æmol/mmol creat) Control - 5.8ñ0.9, Malnour. - 37.3ñ5.7, Maras. - 26.0ñ7.1, Mar/Kwash. - 57.3ñ13.0, Kwah. - 32.6ñ7.3. The MA levels were maintained at discharge. Creatinine levels on admission were significantly lower than normal, they were increased at discharged. We conclude that the urinary MA output of severely malnourished children is significantly higher than normal; this is probably indicative of their burden of toxins. The high MA output at discharge is possibly as a result of oxidant stress imposed by the high polyunsaturated fat content of the recovery diet (AU)