Mercury-induced UDP-glucuronyltransferase (UDPGT) activity in mouse kidney

Administration of mercuric chloride to young adult mice produced a significant increase in the activity of renal UDP-glucuronyltransferase (UDPGT) measured with harmol as the acceptor substrate. This was observed 10 days after a daily oral dose of HgCl2 (6 micrograms Hg2+/g body wt.). The increase in UDPGT activity was correlated with an accumulation of mercury in the renal tissues and was accompanied by an increase in the apparent Vmax of the glucuronidation reaction without a change in the apparent Km values for harmol or UDPGA. Parallel studies with mercuric sulfide however showed negligible retention of mercury in both the liver or kidney nor was there any change in UDPGT activity compared to control values. The difference in solubilities of the two mercuric salts may be responsible for this observation. The possible mode of activation of UDPGT by mercury treatment is discussed.