Effect of estradiol on the activities of ornithine decarboxylase and S-adenosyl-methionine decarboxylase in tissues of ovariectomized rats.
Polyamines play an important role in cellular growth and differentiation. Ornithine decarboxylase (ODC) and S-adenosyl-methionine decarboxylase (SAMD) catalyze the rate-limiting steps of polyamine formation. Many hormones have been known to affect these decarboxylase activities in their target tissues. This study investigated the effect of estradiol (E2) on the activities of ODC and SAMD and on the growth of three estrogen receptor-containing organs: uterus, kidney and liver. Two weeks after ovariectomy, Sprague-Dawley rats received a subcutaneous injection of E2 (10 micrograms/rat). The ODC activity and organ weight were determined at various intervals after E2 administration. The E2 treatment increased the weight of uterus but not that of liver and kidney. In the uterus, ODC activity showed biphasic increases at 6 h and 16-24 h respectively after E2 injection. Renal ODC activity increased gradually and peaked at 18-24 h whereas hepatic ODC activity remained unchanged. Daily injection of E2 over a 3-day period provoked an increase of uterine weight, uterine ODC and SAMD activity. The same treatment also increased renal ODC activity, however it had no effect on the renal SAMD activity and the kidney Our results indicate that E2 has different effects on the activities of ODC and SAMD in three organs tested, and the increase of ODC activity is not necessarily correlated with the tissue growth.
Wing
L Y
LY
Department of Physiology, National Cheng Kung University Medical College, Tainan, Taiwan, R.O.C.
D012437:Adenosylmethionine Decarboxylase / Q000032:analysis*; D000818:Animals; D015317:Biogenic Polyamines / Q000502:physiology; D002262:Carboxy-Lyases / Q000032:analysis*; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D009955:Ornithine Decarboxylase / Q000032:analysis*; D010052:Ovariectomy; D051381:Rats; D011919:Rats, Inbred Strains
D015317:Biogenic Polyamines; D004958:Estradiol; D002262:Carboxy-Lyases; D009955:Ornithine Decarboxylase; D012437:Adenosylmethionine Decarboxylase