镉对大鼠肾皮质结合反应的影响

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.

EFFECTS OF CADMIUM ON THE CONJUGATION OF RAT KIDNEY CORTEX

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 10⁷mol/L to 10³mol/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.