EFFECTS OF CHRONIC FLUORIDE TOXICITY ON THE MORPHOLOGY OF DUCTUS EPIDIDYMIS AND THE MATURATION OF SPERMATOZOA OF RABBIT

This study used light and scanning electron microscopy to observe the effect of chronic fluoride toxicity on the structure of the ductus epi didymis, testis and spermatozoa in rabbit. The rabbits were treated wi th 10 mg NaF/kg body weight/day far 20 and 23 months. Serum fluoride w as estimated by the fluoride ion-specific electrode method. Fluoride l evels in the sera of both 20 and 23-month treated rabbits were signifi cantly increased (P < 0.001). Loss of stereocilia, significant decreas e (P < 0.001) in the height of the pseudostratified columnar epitheliu m and significant increase (P < 0.001) in the diameter of both the cap ut and cauda ductus epididymis were observed only in the 23-month fluo ride treated rabbits. The decreases in the epithelial cell height (P < 0.01) and the tubular diameter (P < 0.001) of the testis were signifi cant only in 23-month treated animals. Spermatozoa in the lumen of the testis of both treated groups of animals and in the caput and cauda d uctus epididymis of 20-month treated animals appeared normal, but sper matozoa in the caput and cauda ductus epididymis of 23-month treated a nimals were fragmented. In the 23-month fluoride treated rabbits, the weights of the caput and cauda epididymis were significantly reduced ( P < 0.025) and there was also a reduction in the number of secretory g ranules in these organs. The structural changes observed in the caput and cauda ductus epididymis might adversely affect the maturation of s permatozoa.