Effect of orchidectomy and testosterone substitution on enzyme activities and DNA content in rat liver and epididymal fat.
Orchidectomy of rats resulted in increased concentration and whole organ amount of DNA both in the epididymal fat pad and liver. Liver hexokinase (HK) and phosphofructokinase (PFK) activities were raised after orchidectomy, but were normalized by testosterone substitution. Several glycolytic enzymes, and fumarase and aspartate aminotransferase were increased by orchidectomy in epididymal fat. Most of the enzyme changes tended to normalize after testosterone administration. Activities of NADPH generating enzymes were increased after orchidectomy both in liver and epididymal fat. When related to DNA, several enzyme activities in both tissues fell following castration. However, liver HK, PFK and NADPH generating enzymes, as well as epididymal fat HK and isocitrate dehydrogenase were elevated after castration also when related to DNA. The results suggest that the influence of testosterone on cell proliferation is organ-specific. The observed enzyme alterations after orchidectomy might partly explain fat accumulation and hyperlipoproteinemia encountered in castrates.
D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D002369:Castration; D002455:Cell Division / Q000187:drug effects; D002952:Citric Acid Cycle; D004247:DNA / Q000378:metabolism; D004822:Epididymis / Q000166:cytology / Q000201:enzymology*; D006019:Glycolysis; D008099:Liver / Q000166:cytology / Q000201:enzymology*; D008297:Male; D009249:NADP / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013739:Testosterone / Q000494:pharmacology*
D000596:Amino Acids; D013739:Testosterone; D009249:NADP; D004247:DNA