Glucuronidation in Cultures of Human Skin Epithelial Cells

Abstract. Glucuronidation of p‐aminophenol, p‐nitrophenol and bilirubin has been investigated in cultures of human skin epithelial cells (HE cells) and human skin fibroblasts (FB) and in homogenates from the same cells. HE cells in culture glucoronidated p‐aminophenol and p‐nitrophenol at rates of about 5 and 10 nmol/mg cell protein per h respectively. Bilirubin was not conjugated by HE cells. In homogenates from HE cells supplemented with UDP glucuronic acid (UDPGA) both p‐aminophenol and p‐nitrophenol were glucuronidated at about the same rate as by living cells in culture. Assuming that the transferase activity is the same in the whole cells compared to the homogenates, transferase activity and not UDPGA production may be the limiting factor in glucuronidation of p‐aminophenol and p‐nitrophenol in these cells. The glucuronidation rate of HE cells was not increased by benzpyrene or benzanthrazene. FB did not glu‐curonidate p‐aminophenol, p‐nitrophenol or bilirubin.