Drug transporters and the BTB

The blood-testis barrier (BTB) divides the seminiferous epithelium into the basal compartment and the apical compartment, the latter being where meiosis and germ cell development take place. The BTB acts as an immunological barrier with unwanted molecules actively transported out of the apical compartment by efflux pumps. Su and colleagues sought to investigate the mechanism by which drugs and chemicals enter the apical compartment by knocking-down the drug transporter Oatp3 and 3 other solute carrier transporters using RNAi. Even though Oatp3 is an integrated component of adhesion complexes in the BTB, its knock-down did not impede Sertoli cell tight junction barrier function. The knock-down of Oatp3 did, however, impede the entry of [3H]adjudin, a toxicant to spermatogenesis, across the BTB. Drug entry is thus not mediated by the disruption of the tight junction barrier, but is controlled by influx pumps. Su et al. (2011) Journal of Endocrinology 209 337–351.

Read the full article at: DOI:10.1530/JOE-10-0474.