Effect of mercury on porcine ovarian granulosa cells in vitro

Abstract

The objective of this in vitro study was to examine dose–dependent changes in the secretion activity [progesterone (P4) and insulin-like growth factor–I (IGF–I)] of porcine ovarian granulosa cells after experimental mercury (Hg) administration, including its apoptotic potential so as to ascertain the possible involvement of Hg in steroidogenesis. Ovarian granulosa cells were incubated with mercuric chloride [mercury (II) chloride or HgCl2] at the doses 50–250 μg mL−1 for 18 h and compared with control group without Hg addition. Release of P4 and IGF–I by ovarian granulosa cells was assessed by RIA and apoptosis by TUNEL assay. Observations show that P4 release by granulosa cells was significantly (P < 0.05) inhibited at all the doses, while IGF-I release was not affected at any of the doses used, although a decreasing trend in the release of IGF–I was noted in comparison to control. An increasing trend of apoptosis of granulosa cells was noted, the difference being significant (P < 0.05) only at the dose 130 μg mL−1 HgCl2, in comparison to control. Obtained data suggest a direct effect of Hg on the release of steroid hormone progesterone but not growth factor IGF-I, and a dose-dependent effect on apoptosis of porcine ovarian granulosa cells. Results indicate the interference of Hg in the pathways of steroidogenesis and apoptosis of porcine ovarian granulosa cells.