Hazards of nicotine on the uterus of albino rat and the possible ameliorative role of human chorionic gonadotropin (hCG)

Introductions: Smoking is an important cause of increased mortality and morbidity in the developing countries. Nicotine in cigarette smoke is one of the toxic substances which impair the fertility.
So, the aim of this work was to study the histological changes induced by nicotine hydrogen tartrate on the endometrium of albino rat and the possible ameliorative effect of human chorionic gonadotropin (hCG).
Material and Methods: Forty females of Wister albino rats in the normal estrous cycle were selected and used for the experiment. The experimental animals were randomly divided into four groups, each one including 10 female rats. The experiment period was extended to four weeks.
Group I was (control group). Group II (Nicotine treated group) was subcutaneously (SC) injected by nicotine hydrogen tartrate as 8 mg/rat three times/week for four weeks. Group III (Nicotine and hCG) was subcutaneously injected with the previous dose of nicotine together with hCG (pregnyl). HCG was subcutaneously injected as 2 IU/rat/day for four weeks. Group IV (hCG group) was subcutaneously injected only with hCG as 2.0 IU/rat/day for four weeks. The specimens were prepared for light and scanning electron microscopic examinations, and morphometric measurements.
Results: Nicotine induced decrease in the thickness of the endometrium. The height of the surface epithelium was decreased, the endometrial stromal cells were disrupted and had congested blood vessels. The endometrial glands became small and atrophied. The endometrium showed apparent increase in collagen fibers, a weak PAS reaction and highly positive immunohistochemical staining KI 67. Scanning electron microscopic examination revealed flattening of the surface epithelial cells with absent apical microvilli and apparent decrease in the number of pits of the glands. Concomitant administration of nicotine and hCG showed marked improvement in the structures of the endometrium as compared with that of the nicotine-treated group.
Conclusion: Nicotine altered the structure of the endometrium and concomitant administration of hCG with nicotine improved it.