Influence of estrogen treatment on hepatic cystathionine synthase and cystathionase of female rats fed varying levels of vitamin B-6.
Diets containing 8, 4, 2, or 0 mg vitamin B-6/kg were fed to intact, female rats designated high-, medium-, low-, and deficient-diet groups, respectively. After receiving the diets for 2 weeks, each group was subdivided so as to receive scheduled subcutaneous injections of corn oil with or without estradiol benzoate (Es and NoEs rats, respectively). In experiment 1, rats were fed ad libitum and injections given daily for 2 weeks. In experiment 2, rats were pair-fed and injections given every other day for 3 weeks. Es injections contained 10 microgram and 20 microgram of estradiol benzoate in experiments 1 and 2, respectively. Hepatic cysthionine synthase (CStase) and cystathionase (CNase) activities were determined both with and without exogenous pyridoxal-5-phosphate (stimulated and basal activities, respectively). Regardless of estradiol treatment, the deficient-diet decreased food intake, weight gain, and the basal and stimulated activities of both enzymes with the exception of stimulated CNase activity in Es rats. Estradiol reduced stimulated CNase activity in the medium- and high-diet groups in experiment 1. In experiment 2, estradiol reduced basal CNase activity of all diet groups and reduced stimulated CNase of low- and high-diet groups. It had little effect on CStase activity.
D000818:Animals; D001835:Body Weight; D003541:Cystathionine beta-Synthase / Q000378:metabolism*; D003542:Cystathionine gamma-Lyase / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D006836:Hydro-Lyases / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008190:Lyases / Q000378:metabolism*; D011736:Pyridoxine / Q000008:administration & dosage; D051381:Rats; D026681:Vitamin B 6 Deficiency / Q000378:metabolism
D004958:Estradiol; D008190:Lyases; D006836:Hydro-Lyases; D003541:Cystathionine beta-Synthase; D003542:Cystathionine gamma-Lyase; D011736:Pyridoxine