Evidence for a defective seminiferous tubule barrier in testes of Tfm and Sxr mice.

The competence of the seminiferous tubule barrier was evaluated by determining the sucrose space in isolated testis preparations obtained from adult wild-type mice and from mutants having defects in spermatogenesis. The distribution of [3H]sucrose in testes from wild-type mice was in a space which constituted 18.5% of the [14C]urea space. The corresponding sucrose space in testes from Tfm/Y and Sxr/+ sterile mutants was elevated to 57.7% and 52.0%, respectively. Independent approaches to detect an impairment in the seminiferous tubule barrier of testes from Tfm/Y mice consisted of estimations of the osmotic barrier to hypertonic LiCl, using histological techniques, and determination of the testis sucrose space in vivo. With both approaches, results obtained supported the presence of an impaired barrier in testes of Tfm/Y mice. The sucrose space was within normal limits in testes of the other mutants examined, which were defective in spermatogenesis. The results do not provide any evidence for an impaired barrier in testes of mice having Movbr/Y and Gy/Y mutations, or the t6twl genotype.