Activation of hepatic microsomal glucuronyltransferase from gunn rats by exposure to light

Exposure of hepatic microsomes from icteric and nonicteric rats to 250 foot candles of blue fluorescent light for 4 hours at 4–6°C significantly increased the activity of UDPglucuronyltransferase activity using p-nitrophenol as a substrate. The light exposure reduced serum bilirubin concentration from icteric rats or bilirubin of fortified human serum albumin by 70 per cent but there was no difference in light activation of hepatic microsomes from icteric or nonicteric rats. Light exposure also decreased the activation of UDPglucuronyltransferase produced by Triton X-100.