EFFECT OF INTRATESTICULAR INJECTION OF SODIUM-FLUORIDE ON SPERMATOGENESIS

The potential of sodium fluoride to affect spermatogenesis in the rat was assessed by intratesticular injection. Experimental rats' left tes tis was injected with sodium fluoride (50, 175 and 250 ppm) in vehicle (0.9% physiological saline); control testes were injected with vehicl e. The right testis served as a non-injected control. Testicular tissu es collected 'at' and 'distal ts' the injection site and from the non- injected control testes were evaluated microscopically 24 hr and 1, 2 and 3 wk post-injection. Testicular tissues obtained at and distal to the injection site in all fluoride-injected groups resembled tissues c ollected from corresponding areas in the controls. Seminiferous tubule damage observed in both the vehicle-injected control testes and the f luoride-injected testes but not in the non-injected testes was attribu ted to injection trauma. Polymorphonuclear leucocyte infiltration was observed 24 hr post injection only at the injection site in the vehicl e- and fluoride-injected groups. Leydig cells were unaffected. Leucocy te infiltration with seminiferous tubule damage was not considered to be a fluoride treatment-related effect because it was observed in both vehicle- and fluoride-injected testes. The results demonstrate that s permatogenesis in the rat is not adversely affected by direct exposure to fluoride at levels 200 times greater than those under normal condi tions. Published by Elsevier Science Ltd.