Alcohol alters blood-testis barrier function in an in vitro model.

Abstract

Objective: This study aims to investigate the impact of alcohol on blood-testis barrier (BTB) integrity using a novel in vitro model and to elucidate potential nonhormonal mechanisms underlying alcohologenic reversible azoospermia.

Design: Primary rhesus macaque Sertoli cells were exposed to ethanol to evaluate dose-dependent effects on BTB integrity. Barrier function was assessed through electrical resistance and permeability assays, with recovery evaluated after a 48-hour withdrawal period. Gene expression of Sertoli cells and tight junction markers and cytokine levels associated with barrier degradation were analyzed.

Subjects: Primary rhesus macaque Sertoli cells were used.

Exposure: Clinically relevant concentrations (10, 60, and 100 mM), equivalent to 1-2 drinks to requiring hospitalization, of ethanol were used.

Main outcome measures: The main outcome measures were BTB integrity and permeability, assessed via transepithelial electrical resistance and Dye Flux assays, recovery of barrier function after ethanol withdrawal, gene expression changes in Sertoli cells and tight junction markers, and cytokine levels associated with barrier impairment. These metrics evaluated the functional and molecular impacts of in vitro ethanol exposure on the BTB.

Results: Ethanol exposure was associated with a dose-dependent decrease in BTB integrity, with partial recovery observed at lower concentrations (10 and 60 mM) after 48 hours of withdrawal, but not at 100 mM. Additionally, ethanol increased the expression of key Sertoli cells and tight junction genes such as SOX9 and CLDN3, and elevated cytokines associated with barrier degradation at higher concentrations.

Conclusion: Clinically relevant ethanol concentrations reversibly disrupt BTB function through a nonhormonal mechanism, with partial recovery at lower concentrations. These findings provide novel insights into the role of BTB dysfunction in alcohologenic reversible azoospermia.