Testing the potential of sodium fluoride to affect spermatogenesis: a morphometric study

This study provides quantitative information on the effect of sodium fluori de (NaF) on the testes of F-1 generation male rats exposed in utero and dur ing lactation to NaF at one of Four concentrations (25, 100, 175, 250 ppm). At weaning, the F-1 generation males were exposed to NaF in their drinking water for 14 weeks, after which time testicular tissues were perfusion-fix ed with glutaraldehyde and observed after being embedded in plastic. The se miniferous tubules comprised 89%, 87%, 88%, 88% and 88% of the total testis volume while the interstitial space occupied 9.3%, 11.2%, 10.2%, 9.8% and 9.9% of the total testis volume for the 0, 25, 100, 175 and 250 ppm NaF tre atment groups, respectively. Statistically significant differences between control and NaF-treated rats were not observed with respect to absolute vol ume of the seminiferous tubules, interstitial space, Leydig cells, blood ve ssels boundary layer, lymphatic space, macrophages, tubular lumen or absolu te tubular length and absolute tubular surface area, mean Sertoli cell nucl eoli number per tubular cross-section, mean seminiferous tubule diameter an d the mean height of the seminiferous epithelium. A statistically significa nt decrease in the absolute volume and volume percent of the lymphatic;endo thelium was observed in the 175 and 250 ppm NaF-treated groups and in the t esticular capsule in the 100 ppm NaF-treated groups. The significance of th is finding is unknown at the present time. Overall, the quantitative inform ation obtained suggests that exposure to NaF at the doses used in the prese nt study does not adversely affect testis structure or spermatogenesis in t he rat. (C) 1998 Elsevier Science Ltd All rights reserved.