Localization of plasma membrane bound NTPDases in the murine reproductive tract

Extracellular nucleotides might influence aspects of the biology of reproduction in that ATP affects smooth muscle contraction, participates in steroidogenesis and spermatogenesis, and also regulates transepithelial transport, as in oviducts. Activation of cellular nucleotide purinergic receptors is influenced by four plasma membrane-bound members of the ectonucleoside triphosphate diphosphohydrolase (E-NTPDase) family, namely NTPDase1, NTPDase2, NTPDase3, and NTPDase8 that differ in their ecto-enzymatic properties. The purpose of this study was to characterize the expression profile of the membrane-bound NTPDases in the murine female and male reproductive tracts by immunological techniques (immunolabelling, Western blotting) and by enzymatic assays, in situ and on tissue homogenates. Other than the expected expression on vascular endothelial and smooth muscle cells, NTPDase1 was also detected in Sertoli cells and interstitial macrophages in testes, in ovarian granulosa cells, and in apical cells from epididymal epithelium. NTPDase2 was largely expressed by cells in the connective tissue; NTPDase3 in secretory epithelia, and finally, NTPDase8 was not detected in any of the tissues studied here. In addition, NTPDase6 was putatively detected in Golgi-phase acrosome vesicles of round spermatids. This descriptive study suggests close regulation of extracellular nucleotide levels in the genital tract by NTPDases that may impact specific biological functions.