Variations in microsomal parameters of intact and regenerating rat liver with time and on feeding high carbohydrate diets.
Adult rats of either sex and mature females ovariectomized 44 days earlier, were partially hepatectomized under ether anesthesia, leading to two-thirds organ removal. The respective controls were incised and the livers manipulated by hand. At specified p.o. periods, hepatic microsomal total protein, cytochrome P-450 and activities of the enzymes, aminopyrine demethylase and benzo[a]pyrene hydroxylase were determined for the respective pairs and submitted to analysis of variance. The data are expressed as ratios of the sham-operated to the partially hepatectomized group mean values on a percentage basis. For one male series, cytochrome P-450 and the 2 enzyme activities were significantly elevated with the intact rats at 72 and 96 h and 10 days and in yet another series of the same sex, the findings were similar except that only the cytochrome level of the controls was increased at day 10; the ratios normalized by day 21. As screened in a few groups, the changes in microsomal NADPH cytochrome c reductase were not noteworthy. Possible latency periods were shorter for the female series and the hydroxylase activity was elevated in the intact liver microsomes over test periods of 24 h to 10 days. In general, although a trend of increased parameter value for the intact group was apparent and in agreement with several published reports, statistical significance could not be substantiated in many instances, wide variations and sporadic data being encountered. None of the intact group changes in the constants were significant with the ovariectomized series. The effect of an inducer, phenobarbital, was determined in relation to the 10 day-ratios derived for males fed a casein based control diet as such and supplemented with 30 wt % each of glucose, fructose, galactose, maltose and lactose, the last one being screened only in partially hepatectomized rats. Phenobarbital was injected i.p. daily at 80 mg/kg on the last 3 days. Among other changes noted with the respective ratios, each of the intact groups displayed remarkable elevations in the total protein content. Additional comparisons are also advanced for the individual group parameter findings in relation to the control diet- and the 30% glucose-fed animals.
Gershbein
L L
LL
Biochemical Laboratories, Northwest Institute for Medical Research, Chicago, IL 60634.
D000633:Aminopyrine N-Demethylase / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D001579:Benzopyrene Hydroxylase / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D005260:Female; D006498:Hepatectomy; D008115:Liver Regeneration; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism*; D010052:Ovariectomy; D051381:Rats; D012737:Sex Factors
D004040:Dietary Carbohydrates; D003577:Cytochrome P-450 Enzyme System; D001579:Benzopyrene Hydroxylase; D000633:Aminopyrine N-Demethylase