Uptake studies, using radioactive labelled glucuronides, have demonstrated the ability of 4‐nitrophenyl glucuronide and phenolphthalein glucuronide to enter isolated rat hepatocytes. Of these glucuronides 4‐nitrophenyl glucuronide was distributed in a similar manner to O‐methylglucose, whereas phenolphthalein glucuronide was bound to cellular constituents. Phenolphthalein glucuronide had an effect on the conjugation of harmol in the isolated hepatocytes when glucuronidation was found to be markedly inhibited and sulphation slightly stimulated. The glucuronidation of 4‐nitrophenol, 4‐methylumbelliferone and harmol in native microsomes was inhibited by phenolphthalein glucuronide. 4‐Nitrophenyl glucuronide and also naphthyl glucuronide were without effect both in hepatocytes and microsomes. In control hepatocytes harmine was metabolized to form harmolsulphate mainly. Phenolphthalein glucuronide only affected this metabolic pattern to a minor extent. However, in hepatocytes from phenobarbital treated rats, where the rate of harmine metabolism is increased about five times and the main metabolite is harmol glucuronide, phenolphthalein glucuronide inhibited the formation of the conjugate with a concomitant increase in free harmol.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.