title: Cobalt-induced hormonal and intracellular alterations in rat ovarian fragments in vitro.
abstract: The objective of this in vitro study was to examine dose-dependent changes in the secretion activity (progesterone, 17β-estradiol and insulin-like growth factor-I) of rat ovarian fragments after experimental cobalt (Co) administration including the apoptotic potential of Co on rat ovarian fragments by evaluating the expression of apoptotic markers Bax and caspase-3. Ovarian fragments were incubated with cobalt sulphate (CoSO4.7H2O) at the doses 90, 170, 330 and 500 μg.mL(-1) for 24 h and compared with control group without Co addition. Release of progesterone (P4) 17β-estradiol and insulin-like growth factor-I (IGF-I) by ovarian fragments was assessed by RIA, expression of Bax and caspase-3 by SDS-PAGE and Western blotting. Observations show that P4 release by ovarian fragments was significantly (P < 0.05) inhibited after cobalt sulphate addition at higher doses 170-500 μg.mL(-1) used in the study in comparison to control. However, cobalt sulphate addition did not cause any significant change in the release of 17β-estradiol by ovarian fragments at all the doses used in the study (90-500 μg.mL(-1)) in comparison to control. On the contrary, IGF-I release by ovarian fragments was significantly (P < 0.05) stimulated after cobalt sulphate addition at the lowest dose 90 μg.mL(-1) in comparison to control, while other doses did not cause any significant change. Also, addition of cobalt sulphate decreased the expression of both the apoptotic peptides Bax and caspase-3 at the higher doses 170, 330 and 500 μg.mL(-1), but not at the lowest dose 90 μg.mL(-1) used in the study. Obtained results suggest Co induced (1) inhibition in secretion of steroid hormone progesterone, (2) dose-dependent increase in the release of growth factor IGF-I, and (3) decrease in the expression of markers of apoptosis (Bax and caspase-3) of rat ovarian fragments.
authors.affiliation: a Department of Life Science & Bioinformatics , Assam University , Silchar , India.
authors.forename: Shubhadeep
authors.initials: S
authors.lastname: Roychoudhury
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Sirotkin
authors.forename: Robert
authors.initials: R
authors.lastname: Toman
authors.forename: Adriana
authors.initials: A
authors.lastname: Kolesarova
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000378:metabolism; D003035:Cobalt / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000378:metabolism; D005260:Female; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D009924:Organ Culture Techniques / Q000379:methods; D010053:Ovary / Q000187:drug effects* / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism; D017208:Rats, Wistar; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: C494828:Bax protein, rat; D051028:bcl-2-Associated X Protein; D003035:Cobalt; D011374:Progesterone; D004958:Estradiol; D007334:Insulin-Like Growth Factor I; D053148:Caspase 3; C026305:cobalt sulfate
keywords: Cobalt; apoptosis; ovarian fragments; rat; secretion activity