镉对大鼠肾皮质结合反应的影响

EFFECTS OF CADMIUM ON THE CONJUGATION OF RAT KIDNEY CORTEX

通过体内和体外试验分别研究了镉对肾皮质微粒体谷胱甘肽转移酶(GST)及游离肾近曲小管细胞中葡萄糖醛酸(GA)结合反应的影响.结果表明:(1)体外试验中,在10^(-7)—10^(-3)mol/L浓度范围内,镉可抑制肾皮质微粒休GST活力;(2)体内腹腔注射CdCl_2(2.4mg/kg,连续3天)后,大鼠肾皮质GST活力无明显改变;(3)按同样方式腹腔注射CdCl_2后,可降低游离肾近曲小管细胞中GA和7-羟基香豆素(7-HC)的结合反应;(4)体外试验中,低浓度镉(10^(-7)mol/L)可使肾皮质细胞中GA和7-HC的结合反应增强,而在10^(-6)—10^(-2)mol/L浓度范围内,镉可降低GA和7-HC的结合反应.

The effects of cadmium on two kinds of conjugation reaction in rat kidney cortex in vivo and in vitro were studied. One was kidney cortex microsomal glutathione S-transferase (GST), and the other was glucuronic acid(GA)conjugation in isolated kidney cortex cells. It was found: l). Cadmium could inhibit kidney cortex microsomal GST activities in vitro under Cd2+ concentration from 10~7mol/L to 10~3mol/L|2). GST activity was ' not markedly changed in vivo after the ip injection of cadmium(2.4mg(kg·d)-l for 3 days); 3). When CdCl2 was administered to rats in vivo by ip injection in the same way it could markedly decrease the conjugation of glucuronic acid with 7-hydroxycoumarin in isolated rat kidney cortex cells; and 4).Lower Cd2+concentration (10-7mol/L)could increase the conjugation of GA with 7-HC in isolated rat kidney cortex cells in vitro, but higher Cd2+ concentrations(10-6mol/L-10-2mol/L)could markedly decrease the conjugation of GA with 7-HC in vitro.