SERTOLI-CELL BARRIER DYSFUNCTION AND SPERMATOGENETIC CYCLE BREAKDOWN IN THE HUMAN TESTIS - A LANTHANUM TRACER INVESTIGATION

The introduction of nitrate of lanthanum in fixative solutions for tes ticular biopsies improves ultrastructural observations of the blood-te stis barrier. In complete (normal) spermatogenesis, junctional special izations impede the diffusion of lanthanum into the adluminal compartm ent. They clearly exhibit a three-storied disposition in orthogonal se ctions. In maturation arrest, lanthanum passes easily through the junc tional specializations surrounding the germ cells and up to the lumen. In irregular hypospermatogenesis, the Sertoli cell barrier is permeab le, but diffusion of the tracer is less significant and variable. Unex pectedly, in germ cell aplasia, the barrier remains efficient.