Mirex-induced adaptive liver growth: a corticosterone-mediated response.
The adaptive liver growth response was investigated in intact and adrenalectomized rats. When adult male rats were given a single oral dose of mirex (100 mg/kg body weight) there was a 72% increase in relative liver weight (RLW) in 72 hr. Based on [3H]-thymidine [( 3H]TdR) incorporation into hepatic DNA, there was also a wave of DNA synthesis which peaked at 48 hr and decreased to essentially control values by 96 hr post mirex dose. In mirex-dosed adrenalectomised (Adx) animals, the RLW was increased by only 38% and there was sustained DNA synthesis. When mirex-dosed Adx rats were given corticosterone supplements, the RLW response was similar to the RLW response in intact mirex-dosed rats. However, the 48-hr DNA synthesis peak seen in intact mirex-dosed rats was eliminated. From these data it is suggested that mirex-induced adaptive liver growth has two components: a hypertrophic component which is mediated by corticosterone, and a hyperplastic component which is independent of corticosterone.
D000315:Adrenalectomy; D000818:Animals; D003345:Corticosterone / Q000494:pharmacology*; D004261:DNA Replication / Q000187:drug effects; D007306:Insecticides / Q000494:pharmacology*; D007700:Kinetics; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008917:Mirex / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D007306:Insecticides; D003345:Corticosterone; D008917:Mirex