Gollamudi R, Prasanna H R, Rao R H, Lawrence W H, Autian J
J Toxicol Environ Health. 1983 Oct-Dec;12(4-6):623-32. doi: 10.1080/15287398309530454.
Liver, kidney, and lung homogenates from 45- and 630-d-old rats were incubated with 0.5 muCi of 14C-labeled di(2-ethylhexyl) phthalate (DEHP) for 40 min at 37 degrees C. Radiochromatogram scans of the ether extracts of the incubated mixtures showed the presence of a peak corresponding to the hydrolytic product monoethylhexyl phthalate (MEHP), in addition to the parent DEHP. Preparations from old animals revealed another radioactive zone along with MEHP. A dramatic reduction in the formation of MEHP was observed only with homogenates of livers from the old animals. It is shown that this difference is probably attributable to differences in Km values of the enzymes from adult and old rats respectively. Protein content in the three tissues did not differ between young and old animals. Formation of MEHP is a major step in the metabolic pathway of the plasticizer DEHP. Impairment of this conversion could possibly alter the rate of its excretion and hence its toxicologic significance.
将45日龄和630日龄大鼠的肝脏、肾脏和肺匀浆与0.5微居里的14C标记邻苯二甲酸二（2-乙基己基）酯（DEHP）在37℃下孵育40分钟。孵育混合物的乙醚提取物的放射色谱扫描显示，除了母体DEHP外，还存在一个与水解产物单乙基己基邻苯二甲酸酯（MEHP）相对应的峰。老年动物的制剂除了MEHP外还显示出另一个放射性区域。仅在老年动物肝脏匀浆中观察到MEHP形成的显著减少。结果表明，这种差异可能分别归因于成年大鼠和老年大鼠酶的Km值不同。年轻和老年动物的这三种组织中的蛋白质含量没有差异。MEHP的形成是增塑剂DEHP代谢途径中的一个主要步骤。这种转化的受损可能会改变其排泄速率，从而改变其毒理学意义。
