Localization of nucleoside transporters in rat epididymis.
The epididymis relies on transporters for the secretion of nucleosides and influence the disposition of nucleoside analogs (NSA). Since these compounds can cross the blood-testis barrier (BTB), it is important to understand if the epididymis reabsorbs NSA drugs. The purpose of this study is to determine the localization of nucleoside transporters expressed within rat epididymis to demonstrate the potential of epididymal reabsorption. Using immunohistochemistry, we determined that equilibrative nucleoside transporter 1 (ENT1) is localized to the basolateral membrane of epithelial cells, ENT2 is expressed in the nucleus of the epithelium and CNT2 is expressed by basal cells. The expression pattern for these transporters suggests that nucleosides are able to access the epithelial cells of the epididymal duct via the blood, but not from the lumen. We did not find any evidence for a transepithelial reabsorption pathway indicating the NSA drugs that cross the BTB remain within the epididymis.
Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ, 85721, USA.
David M
DM
Klein
Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ, 85721, USA.
Marcus C
MC
Harding
Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ, 85721, USA.
Meghan K
MK
Crowther
Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ, 85721, USA.
Nathan J
NJ
Cherrington
D000818:Animals; D001814:Blood-Testis Barrier / Q000201:enzymology*; D002352:Carrier Proteins / Q000378:metabolism*; D004822:Epididymis / Q000166:cytology / Q000201:enzymology; D033721:Equilibrative Nucleoside Transporter 1; D007150:Immunohistochemistry; D008297:Male; D026901:Membrane Transport Proteins / Q000378:metabolism*; D009705:Nucleosides / Q000493:pharmacokinetics / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D002352:Carrier Proteins; D033721:Equilibrative Nucleoside Transporter 1; D026901:Membrane Transport Proteins; D009705:Nucleosides; C438652:Slc29a1 protein, rat; C065171:cif nucleoside transporter
male genital tract; nucleoside transport; reproductive toxicology; xenobiotic transporter