The extensive tight junctions that link Sertoli cells were studied in testes of monkeys (Cercopithecus aetiops) in conventional thin sections, lathanum-perfused specimens, and free-fracture replicas. The results demonstrated that tight junctions linked Sertoli cells from the base, and in conventional sections they were identifiable as punctate points of occlusions. Colloidal lanthanum penetrated many of these points. Freeze-fracture replicas showed a large number of strands and displayed various degrees of complexity; this variability was associated with the exposed area. Areas with less organized and regularly spaced strands, breakdown of strands, and organizing and disorganizing particles were related to the dynamic aspect of these junctions, which continuously disassembled and reorganized to allow the transfer of germ cells from the basal to the adluminal compartment. This report hypothesizes that the blood-testis barrier may result from the summation of the resistances contributed by a large number of moderately leaky structures arranged in series. The coexistence of septate with tight junctions was never observed, since all strands were of the tight junction type. These were frequently associated with communicating junctions.
ASJC Scopus subject areas
- Molecular Biology