Dr. Marim Fayz Abdow :: Publications:

Summary This work was designed to study the preand postnatal harmful effect of nicotine tartrate on histological and ultrastructure of the heart and aorta in albino rat pups . At 18th day and 20th day of gestation ,then at 21 and 45 day after birth . After subcutaneous injection of nicotine tartrate to their mothers , from the first day of gestation untill weaning (21 day after delivary) , in a dose of 6mg /kg/day given once daily. We also investigate the possible protective role of ascorbic acid against the nicotine , when it is injected in in a dose of 3mg/kg/day to pregnant rats in the same time with the nicotine tartrate . This researsh contained 12 groups to both heart and aortic specimen: In the prenatal and postnatal control groups ,the cardiac myocardium formed of branched and anastomosed muscle fibrils , with single central rounded nuclei of cardiac muscle cell ,and appearing flat nuclei of interstitial fibroblast ,as seen by light microscope. But with Masson's trichrome stain , there is minimal amount of collagen between the muscle fibrils. While by electron microscopic examination , the sarcomere (structural unit of myocardium) formed of a light band called (I) band , having Z line in its center , and a dark band called (A) band , having M line in its center .The mitochondria arranged in sheets between the sarcomere . In light microscopic examination of aortic specimen of control groups of both prenatal and postnatal pups ,there is the tunica intima which formed of single endothelial layer lining the aortic lumen . Tunica media ,formed of regularly arranged elastic lamellae with smooth muscle cell between them (with its single flat nucleus ) .Tunica adventitia formed of connective tissue layer with elastic fibers (not lamellae) . By masson's trichrome stain , the normal amount of collagen fibers appearing between the lamellae of tunica media and outside it in the adventitia . While by electron microscope , regularly arranged elastic fibers appeared with smooth muscle cell between them. By light microscopic examination for the nicotine treated pups of both prenatal and postnatal groups ,the cardiac muscle fibrils showed , marked degeneration , with appearance of wide empty spaces between them, thickening some of them , and diffuse inflammatory cell infilteration . In Masson's trichrome stain , there is considerable amount of collagen between degenerated cardiac muscle fibrils , in postnatal group only . By electron microscopic examination of pre and postnatal nicotine treated groups , there is degenerated , deorganizated and wavy sarcomere of cardiac myocardium . with degenerated mitochondria between them. Congested blood capillaries , with rarified collagen in its wall. In nicotine treated pups of pre and postnatal groups , light microscopic examination of aortic wall showed, erosion of tunica intima , disruption and disarrangement of elastic fibers of elastic lamellae of tunica media ,with spaces appeared between them. Connective tissue increased to high extend outside the tunica media in postnatal groups only. By electron microscopic examination of aortic tissue in all groups , the elastic fibers of the tunica media are fragmented , and occurred between the smooth muscle cells ,which called (Elastolysis) , it was thickened in some specimen .Smooth muscle cell between them have rarified cytoplasm , vacuoles , attenuated nucleus , and degenerated mitochondria . In nicotine plus ascorbic acid treated groups , the myocardium showed signs of improvement in pre and postnatal groups .By light microscope , the cardiac muscle fibrils is partially appeared normal , with nearly normal connective tissue between them. By electron microscope , the sarcomere is normally to high extend , with normal smooth muscle cell between them. Also , aortic tissue appeared normal after ascorbic acid administration .By light microscope , tunica intima reformed lining the aortic lumen ,tunica intima have normal arranged and regular elastic lamellae ,with normal smooth muscle cell between them. The connective tissue decreased outside the tunica media . And by electron microscope, sarcomere appeared normal ,has normal A and I band ,with normal M line and Z line . Smooth muscle cell showed normal cytoplasm and normal nucleus. Conclusions Nicotine tartrate affects the heart and aortic wall of the developing rats , during gestation and postnatal periods . Therefore, exposure to inhaled nicotine tartrate ,either by active or passive smoking ,must be restricted , especially during pregnancy and lactation .In addition , increasing awareness of its hazards is recommended . Vitamin C is a known chelating agent with non-enzymatic antioxidant features , was widely reported to have the ability to protect cells from oxidative stress in nicotine-exposed rats . So , administration of combined nicotine and ascorbic acid , minimize the harmfull effect of nicotine tartrate on developing heart &aorta . .