RESUMEN
The present study was carried out to gain more insight on the effect of nicotine on interstitial tissue and the process of spermatogenesis. Also, the possible reversibility of nicotine effects was studied. Different stereological techniques were employed in a trail of precise assessment of its effects on male fertility. The testes were subjected to light and electron microscopic examinations. The testes of nicotine treated animals reveled remarkable degenerative changes in the interstitial cells of Leydig. The interstitial tissue appeared expanded around the atretic seminiferous tubules, with appearance of interstitial odema, increased number of fibroblastic cells and thickening in the wall of the blood vessels. The ultrastructure of interstitial cell of Leydig declared the drastic effect of nicotine upon this cell. The nucleus appeared dense and irregular in shape. Its chromatin texture was disrupted with distorted outline, which might be interrupted at certain areas. The cytoplasm showed accumulation of lipid droplets, lysosomes, dilated smooth endoplasmic reticulum and damaged mitochondria. The nicotine treated animals revealed an increased volume proportion of the interstitial tissue. Leydig cells nuclei exhibited a significant increase in their nuclear diameter and also in nuclear surface area/total cell surface area. On rehabilitation, the picture appeared to be improved in all histological and stereological parameters to become more or less similar to the control. The ultrastructural study of Leydig cells demonstrated a marked degree of recovery in their nuclear and cytoplasmic features. Also, all the stereological pameters revealed a great improvement