title: Inhibition of sex-steroid hormone induced ornithine decarboxylase and poly(A)-polymerase activities by a GnRH agonist in the rat kidney.
abstract: Recently GnRH and its synthetic agonists were shown to exert extrapituitary actions and inhibit the growth-promoting effects of testosterone and estradiol. In the present study, the long-term effect of GnRH agonist [des-Gly10, D-Ala6-GnRH ethylamide GnRHa] on the steroid-induced renotropic effect was investigated. Gonadectomy of 30-day old male and female rats resulted in the drastic reduction of kidney ornithine decarboxylase (ODC) activity. Injection of testosterone (75 micrograms/rat) or estradiol (1 microgram/rat) to castrated rats significantly increased the enzyme activity at 24 h. Treatment with the GnRH agonist, two doses of 100 micrograms each, caused significant inhibition of the hormone induced ODC activity. Similarly injection of dihydrotestosterone to castrated adult male rats significantly increased poly(A)-polymerase activity at 24 h. Two doses of 100 micrograms of GnRHa caused significant inhibition of DHT induced poly(A)-polymerase activity. These results show that chronic exposure to potent GnRH analogs may have anti-steroidal activity in the kidney.
mesh_terms: D000818:Animals; D013196:Dihydrotestosterone / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D012739:Gonadal Steroid Hormones / Q000494:pharmacology*; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology; D007668:Kidney / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D009713:Nucleotidyltransferases / Q000037:antagonists & inhibitors*; D009919:Orchiectomy; D065108:Ornithine Decarboxylase Inhibitors; D010052:Ovariectomy; D011062:Polynucleotide Adenylyltransferase / Q000037:antagonists & inhibitors*; D051381:Rats; D013739:Testosterone / Q000494:pharmacology
chemical_list: D012739:Gonadal Steroid Hormones; D065108:Ornithine Decarboxylase Inhibitors; D013196:Dihydrotestosterone; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D004958:Estradiol; C010661:surfagon; D009713:Nucleotidyltransferases; D011062:Polynucleotide Adenylyltransferase