In Vitro Changes in Secretion Activity of Rat Ovarian Fragments Induced by Molybdenum

Abstract

The aim of this in vitro study was to examine the secretion activity (progesterone, 17β-estradiol and insulin-like growth factor-I) of rat ovarian fragments after molybdenum (Mo) addition. Rat ovarian fragments were incubated with ammonium molybdate (NH4)6Mo7O24.4H2O at the doses 90, 170, 330 and 500 µg.ml-1 for 24 h and compared with control group without Mo addition. Release of progesterone (P4), estradiol (17β-estradiol) and insulin-like growth factor I (IGF-I) by ovarian fragments was assessed by radioimmunoassay (RIA). Data show that P4 release by ovarian fragments was not affected by (NH4)6.Mo7O24.4H2O addition at all the doses used (90-500 µg.ml-1). However, addition of ammonium molybdate was found to cause a significant (P<0.05) dose-dependent decrease (at the doses 90, 170 and 500 µg.ml-1) in release of 17β-estradiol by ovarian fragments in comparison to control. Also, addition of ammonium molybdate significantly (P<0.05) inhibited IGF-I release at all the doses (90-500 µg.ml-1) used in the study. Results suggest ammonium molybdate induced inhibition in the release of growth factor IGF-I and its dose-dependent effect on secretion of steroid hormone 17β-estradiol but not progesterone. These data contribute to new insights regarding the mechanism of action of Mo on rat ovarian functions.