Effect of repeated injection of somatomedin C on drug metabolizing enzyme activities in rats.
The effect of somatomedin C on the hepatic drug-metabolizing enzyme system in rat liver after sc injection, a clinically applicable dosing route, was studied. Although liver weight was slightly increased after somatomedin C (1 mg/kg) was injected for 7 days, no significant changes were observed in other dosing group (0.1 and 10 mg/kg). There were no significant effects of somatomedin C on cytochrome P-450 and b5 contents, and NADPH-cytochrome c reductase, aminopyrine demethylase, aniline hydroxylase, and ethoxyresorufin deethylase. Additionally, somatomedin C treatment did not affect the activities of 2 alpha-, 2 beta-, 6 beta- and 16 alpha-hydroxytestosterone and androstenedione formation from testosterone. Changes relation to dosing period were also examined with 1 mg/kg of somatomedin C. In this case, hepatic levels of cytochrome P-450 and b5, NADPH-cytochrome c reductase and drug oxidations did not differ significantly among groups treated for 3, 7, or 14 days. These results suggest that somatomedin C has no effect on the hepatic mixed-function oxidase system.
Niwa
T
T
Pharmaceutical and Pharmacokinetic Research Laboratories, Fujisawa Pharmaceutical Co., Ltd., Osaka, Japan.
Naritomi
Y
Y
Kawano
M
M
Ueda-Shimohira
Y
Y
Takeshita
K
K
Shiraga
T
T
Iwasaki
K
K
Noda
K
K
D000818:Animals; D001835:Body Weight; D004334:Drug Administration Schedule; D007279:Injections, Subcutaneous; D007334:Insulin-Like Growth Factor I / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects* / Q000201:enzymology; D009929:Organ Size; D010088:Oxidoreductases / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
D007334:Insulin-Like Growth Factor I; D010088:Oxidoreductases