Function of adrenal gland-zona fasciculata in rats receiving polychlorinated biphenyls

Abstract

The corticosterone plasma level and the storage of organochlorine compounds (OCC) were assessed in mature male rats receiving 250 ppm polychlorinated biphenyls (PCBs)-1221 for 10 wk. The storage of PCBs in the adipose tissue of rats which received 250 ppm PCBs-1221 reached a level of 5.8 ppm as against 0.065 ppm in controls. Organochlorine insecticide storage was also increased in rats receiving PCBs-1221 (0.65 ppm DDT as against 0.29 ppm in controls and 0.15 ppm Dieldrin as against 0.02 ppm in controls) although they did not receive extra amounts of these OCI except the amount currently present in food and water. These data confirm some of our previous findings, i.e., the presence in the animal body of a larger quantity of an organochlorine compound may influence the metabolic clearance rate of other organochlorine compounds. The mean level of corticosterone in these rats was 12.3 μg/100 ml as against 6.2 μg/100 ml in control rats. The difference between the two groups was statistically significant ( P < 0.01). These findings comply with morphological features of hyperfunction of the adrenal zona fasciculata in rats receiving PCBs-1221 which we described in a previous study. The results are interpreted as evidence of the need for a higher level of glucosteroids in defense against the stressor character of PCBs-1221 and perhaps also of the need for catatoxic activity of glucosteroids.