The effects of hexachlorobenzene on circulating levels of adrenal steroids in the ovariectomized rat

Hexachlorobenzene (HCB), is a global pollutant that resists degradation and possesses a propensity to bioaccumulate. However, the effect of HCB on adrenal function remains largely unknown. Thus, circulating levels of adrenal steroids in HCB-exposed (0.0, 1.0, 10.0, or 100.0 mg/kg/day--for 30 days by gavage) adult ovariectomized Sprague-Dawley rats (N = 32) were investigated. A terminal blood sample was collected for HCB residue analysis, and levels of circulating progesterone (P4), corticosterone (CS), and aldosterone (ALD) were quantified. Mean serum CS levels were significantly (P = 0.02) reduced by HCB exposure, starting with the lowest dose group (1.0 mg/kg/day for 30 days), whereas no differences in mean serum P4 and ALD levels were observed. Since it has been argued that the rodent possesses the ability to produce small amounts of cortisol and that levels of this glucocorticoid are altered in pathological states, serum cortisol (C) levels were also measured. Circulating levels of C were significantly lower (P < 0.05) in the highest dose group compared with controls. The presence of C in serum was confirmed by reverse-phase HPLC. These data suggest that even at the lowest dose studied, HCB exposure induces alterations in steroidogenesis of cells of the adrenal cortex inner zone.