The tenacity of the blood-testis and blood-epididymal barriers

Abstract

The blood-testis barrier (Setchell and Waites, 1975; Howards et al., 1976) and the blood-epididymal barrier (Turner, 1979; Turner et al., 1981) prevents blood-borne substances from freely diffusing into the lumen of the seminiferous and epididymal tubules. The structural component of these barriers are the epithelial cell-cell tight junctions known to be present in the seminiferous (Flickinger and Fawcett, 1967; Dym and Fawcett, 1970) and epididymal (Friend and Gilula, 1972; Suzuki and Nagano, 1978) epithelia. Morphological studies of the testis have shown that the ability of these tight junctions to exclude lanthanum from the seminiferous tubule lumen is not impaired by cryptorchism (Hagenas et al., 1977), short-term efferent duct ligation (Osman and Ploen, 1978), or pre-pubertal treatment with oestrogen (Vitale et al., 1973). It appears from these morphological studies then that the cell-cell tight junctions are quite stable to injury, and disruption of this aspect of the blood-testis barrier cannot be called upon as the contributing reason for the antispermatogenic effects of many physiological insults to the testis.