Age dependent accumulation of cadmium in the human ovary

Cadmium accumulation in follicular fluid of women in in vitro fertilization-embryo transfer is higher in smokers

OBJECTIVE

To assess cadmium, a heavy metal in cigarette tobacco, in follicular fluid (FF) of women in IVF-ET, who smoke.

DESIGN

Controlled clinical study.

SETTING

Infertile patients in a hospital IVF-ET program.

PATIENTS

Fifty-one women selected in groups according to smoking habits: nonsmokers (n = 10), passive smokers (n = 17), light smokers (< 15 cigarettes per day, n = 19), and heavy smokers (> or = 15 cigarettes per day, n = 5).

INTERVENTIONS

Ovarian hyperstimulation with GnRH agonist.

RESULTS

The mean +/- SEM level of FF cadmium was higher in smokers (7.93 +/- 0.16 ng/mL) than in nonsmokers (6.73 +/- 0.31 ng/mL), and with a dose-effect of smoking. The individual levels in passive, light, and heavy smoking women also were higher than in nonsmoking women.

CONCLUSIONS

Despite lack of vascularization of the follicle, cadmium accumulation was detectable in FF. Cadmium also could accumulate in oocytes of smokers; it does so, in a dose-dependent manner, in oocytes of cadmium-treated rats. Access to cadmium and other contaminants of cigarette smoke in FF may compromise the quality of oocytes, becoming a risk factor.

Acute cadmium exposure and ovarian steroidogenesis in cycling and pregnant rats

The purpose of this study was to evaluate the effect(s) of acute in vivo cadmium (Cd) exposure on steroidogenesis in rat ovaries during different reproductive states. Sprague-Dawley rats were injected subcutaneously on the day of diestrus, or on day 7 or 16 of gestation with a single dose of 0, 3, or 5 mg Cd/kg bw, and evaluated 24 h later. Serum progesterone and estradiol concentrations were determined. Whole-ovary culture was used to evaluate Cd effects on the production of progesterone, testosterone, and estradiol. Liver, kidney, spleen, ovary, placenta, and blood were analyzed for Cd and iron (Fe) concentrations. No general toxic effects, no disruption of estrous cyclicity, and no change in fetal viability were seen. Histologic evaluation revealed moderate Cd-related thecal congestion in ovaries of pregnant rats. The highest Cd concentrations, except for liver, were found in the fetal portion of the placenta. Interestingly, Cd-related decreases in Fe concentration were found in several tissues from rats in proestrus and on gestation day 8, and in fetal placenta from rats on gestation day 17. Cadmium appears to interfere with normal steroidogenesis at a number of sites in the biosynthetic pathway with serum estradiol concentration and ovarian estradiol production the most affected. Acute Cd effects on steroidogenesis are most severe in rats evaluated in proestrus or in early pregnancy, while in late pregnancy steroidogenesis is relatively unaffected.