Excitatory and inhibitory effects of nitric oxide on the process of evolution of the Cardiomyocyte of rat embryo

According to increased consumption of supplements during pregnancy and the teratogenic impact of some drugs on evolution the vital systems of embryos, in this study to improve the health of the fetus and prevention of cardiovascular abnormalities as the most common cause of infant mortality, we examined the effects of L-Arginine and L-NAME administration on fetal rat heart.

Forty Wister rats, weighing 200-250gr with age of 8 weeks, were divided into 5 groups after observing the vaginal plug. Except the control group, the others were received 2ml/kg normal saline, 200mg/kg L-Arginine, 20mg/kg L-NAME and a mixture of the same doses of L-Arginine & L-NAME respectively on 8 to 11th gestational days via Intraperitoneal. The fetal Hearts were removed on 18th gestational days and were fixed in formalin 10 percent, after tissue preparation and staining method (H&E) histological changes were studied by Light microscopy Olympus Cx31 and software Image tools III.

Despite of the control group, the significant decrease (p <0.05) in the diameter of cells and their nuclei were observed in L-NAME group , L-NAME group also was associated with irregularities in heart muscle structure and intercalated and in the L-Arginine group severe Myogenesis and Angiogenesis was observed.

Results of this study showed that Nitric oxide (NO) in amounts higher or lower than normal is associated with congenital heart diseases. Therefore, drugs and supplements should be used with caution especially during pregnancy.