MORPHOMETRIC EVALUATION OF OVARIAN TISSUE EXPOSED TO PCB CONVENTIONALLY AND IN A SUSTAINED MANNER

摘要

Most natural estrogens are short-lived, do not accumulate in tissue and are easily broken down in the liver. In contrast to natural estrogens, estrogenic drugs such as ethynylestradiol, diethylstilbestrol, synthetic environmental estrogens such as beta-hexachlorocyclohexane, polychlorinated biphenyls (PCBs), and phytoestrogens, are more stable and remain in the body longer than natural estrogens. Because most of these compounds are lipophilic, they tend to accumulate within the fat and tissue of animals and humans. Thus, depending on the natural estrogen levels, environmental estrogens may have different influences (mimicking, or blocking estrogen's effects) on estrogen activities. A total of 14 adult female rats were divided randomly into three groups. Animals in group I (n=4) served as control. Animals in group II (n=5) were injected with PCBs, and animals in group III (n=5) were implanted with TCPL capsules containing PCBs. Pap smears were obtained daily, and at the end of the experimental phase the animals were sacrificed and vital organs as well as reproductive organs were obtained and wet weights were recorded. Significant reductions in ovarian wet weights were found in all animals treated with either sustained release of PCBs or injection of PCBs. Ovarian tissue was further analyzed histologically to determine the effects of PCBs. Histomorphometric data revealed significant reduction (p<0.05) in the total ovarian area of animals treated with PCBs. Measurements of cross-sectional lengths confirmed the reduction seen in the area. Overall, the data suggest that PCB pollutants have produced detrimental effects on endocrine function as well as fertility regardless of the route of administration.