الفهرس 
Nicotine and its hazardous effectsOnly 14 pages are availabe for public view
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Abstract
Despite smoking being a major life style risk factor for osteoporosis, the mechanisms underlying smoking associated bone loss and fractures risk remain poorly understood. Many claims had been made about vitamin E’s potential to promote bone health. So the aim of the present work was to study the effects of nicotine on the metaphysis of the femur and the possible protective role of vitamin E.
Forty five adult male Albino rats were used for this study and were divided into three groups fifteen for each. Group I served as control. Group II received nicotine alone through intraperitoneal injection at a dose of 7mg/kg/d for three months. Group III received nicotine at the same dose of group II together with oral α tocopherol at a dose 60mg/kg/d for three months.
At the end of the experiment the animals were sacrificed. The proximal ends of the metaphyseal region of femur in different groups were dissected, processed and examined for LM. Small specimens about one mm³ from the proximal metaphysis of different groups were taken and processed for scanning electron microscope.
Moreover morphometrical studies were done for cancellous bone thickness, cancellous bone volume, and cortical bone thickness. Measurements of bone mineral contents in different groups were done and statistical analyses for the above measurements were done.
Histological results:
The nicotine treated group (group II) revealed thinning out of the outer cortical bone with some broken areas. Inner cancellous bone showed, thin discontinuous widely separated bone trabeculae, bone necrosis and erosion cavities. An apparent decrease collagen fibers content in cancellous bone trabeculae was detected. Wide bone marrow spaces with numerous adipocytes were also noticed.
Also the morphometrical analysis showed significant decrease in the mean outer cortical bone thickness, the mean trabecular bone thickness and volume and Ca content compared to that of control and protected group III.
The SEM examination of this group showed thinning out of trabeculae of the cancellous bone with crakes, fractures. Irregular arrangements of the collagen fibers could be seen.
In (group III), sign of bone formation was seen in the form of hypercellular active periosteum. An apparent increase in the collagen fibers in the trabeculae of the cancellous bone.
There were significant increases in the thickness of the outer cortical bone, the mean trabecular bone thickness and volume and Ca content.
SEM examinations showed an improvement in the number and thickness of the cancellous bone trabeculae with absence of bony crakes and fractures. Also regular arrangement of collagen fibers could be detected.