Comparative aspects of hepatic UDP-glucuronosyltransferases and glutathione S-transferases in bluegill and channel catfish

1. 1. Microsomal UDP-glucuronosyltransferases (UDPGTs) and cytosolic glutathione S-transferases (GSTs) were examined in bluegill (Lepomis macrochirus R.) and channel catfish (Ictalurus punctatus R.) liver. 2. 2. Hepatic UDPGT activity was of a similar magnitude in both species and was markedly increased by the addition of 0.05–0.2% Triton X-100, however, optimal estimates of activity were obtained when 0.1% detergent was used. 3. 3. Both species exhibited hepatic GST activity toward several structurally dissimilar substrates, suggesting the presence of multiple GSTs. GST activity ranged over three orders of magnitude, depending upon substrate, and was approx. 3-fold higher in the channel catfish than in the bluegill.