Effects of sodium fluoride on embryogenesis of albino rat offsprings II. myocardial toxicity

ABSTRACT

Fluoride is often found in drinking water, so that ingestion of drinking water containing high concentration of fluoride is the main source of human environmental exposure worldwide.Also it occurs in foods, minerals, soils and air. So far, little information is known about the teratogenic effects of sodium fluoride on the development of species. A study was conducted on the influence of sodium fluoride [NaF]on the development of patho-morphological changes in the heart of albino rat offsprings. Three groups of adult albino rats [one male and four females] each were exposed orally to 18mg/kg of sodium fluoride in drinking water for three month. Also, one control group [one male and four females] received distilled water for the same period. By the end of exposure period, one exposed male and two females were isolated and kept in a separate cage to allow mating. Vaginal smears were taken and examined to ensure pregnancy. At 20 days of gestation, the female abdomen was opened and the whole fetuses were examined grossly for the presence of any abnormalities or birth defects then fixed in Bouin's fixative. Sagital sections were made after fixation representing the thoracic region and stained with Haematoxylin and Eosin stain then processed for histopathological assessment by light microscopy. Marked edema, hemorrhage and septal defects in rat hearts offsprings were observed grossly. Sodium fluoride induced pronounced changes on the vasculature expressed by severe dilatation of blood vessels in the thoracic region. Moreover, necrosis of the tunica intima and dystrophic calcification were observed in exposed groups compared to controls. Interstitial myocardial edema expressed by the presence of vacuoles and blue precipitation were observed. Nucleomegaly of the smooth muscle fibers as well as swelling of the myocardial fibers were also observed. In the endothelial cells lining some blood vessels were grown and projected into the lumen forming papillary folds. These observations suggest that sodium fluoride induced marked vascular and myocardial changes and could be toxic to myocardial cells