LONG-TERM ALTERATIONS IN THE PERMEABILITY OF THE BLOOD-TESTIS BARRIERFOLLOWING A SINGLE INTRATESTICULAR INJECTION OF DILUTE AQUEOUS GLYCEROL

The mechanism whereby glycerol exerts its antispermatogenic action is not known. The objective of this study was to determine, with the use of [H-3]inulin and [I-125]albumin by in vivo and in vitro methods, whe ther glycerol exerts its effect by altering the permeability of the bl ood-testis barrier (BTB). Adult male rats received a single intratesti cular injection of either glycerol (10% or 20%; treated) or saline (co ntrol), and 2, 4, 8, 26, and 56 weeks after treatment, either [H-3]inu lin or [I-125]albumin was administered either by infusion or directly to the testicular tissues. Radioactivity was measured in testicular ti ssue, rete testis fluid, and seminiferous tubular fluid. Following in vivo administration, the uptake of [H-3]inulin by seminiferous tubules , rete testis fluid, and seminiferous tubule fluid was significantly g reater in the treated than in the control testes at all times after tr eatment. Radiolabeled inulin, injected into isolated testes or added t o medium in which isolated tubules were incubated, accumulated at sign ificantly higher levels in the seminiferous tubule compartment of trea ted than control tissues. Rete testis fluid from treated testes, colle cted by micropuncture following efferent duct ligation, contained abou t 5- to 13-fold more radioactivity than fluid from controls. Following infusion of 50 mu Ci of [I-125]albumin into the jugular vein, the acc umulated radioactivity was significantly greater in testicular and epi didymal tissues and in the seminiferous tubule fluid from treated than from control animals. In all experiments, the significant differences between treated and control were maintained during the period of 2-56 weeks following glycerol treatment. The results suggest that a single intratesticular injection of dilute glycerol solution alters the perm eability of the BTB to macromolecules such as inulin and albumin, and the effect appears to be permanent.