Talevi R, Zagami M, Castaldo M, Gualtieri R. Redox Regulation of Sperm Surface Thiols Modulates Adhesion to the Fallopian Tube Epithelium1.
Biol Reprod 2007;
76:728-35. [PMID:
17229933 DOI:
10.1095/biolreprod.106.056028]
[Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Sperm that adhere to the fallopian tube epithelium are of superior quality and adhesion extends their fertile life. It has been postulated that periovulatory signals, as yet undefined, promote sperm release. In the in vitro studies described here, we examined the effects of several antioxidants, reportedly present within oviductal fluid, on the modulation of sperm-oviduct adhesion in bovine species. Results showed that 1) the cell-permeant thiols (penicillamine, beta mercaptoethanol, cysteine, and dithiotreitol), as well as the nonpermeant thiol, reduced glutathione, cause adhering spermatozoa to release from the epithelium; 2) thiol action is exerted on spermatozoa; and 3) oxidized glutathione, as well as the non-thiol antioxidants (dimethylthiourea, trolox, superoxide dismutase, and catalase) have no effect. Sperm surface sulfhydryls labeled with iodoacetamide fluorescein showed that spermatozoa devoid of sulfhydryls on the head surface adhered to the fallopian epithelium in vitro, whereas thiol-induced release increased the exposure of sulfhydryls on the sperm head surface. Finally, analysis of capacitation status demonstrated that uncapacitated spermatozoa adhered to the oviduct, and that thiol-induced release of spermatozoa was accompanied by capacitation. In conclusion, thiol-reducing agents in the oviductal fluid may modulate the redox status of sperm surface proteins, leading to the release of spermatozoa selected and stored through adhesion to the fallopian tube epithelium in the bovine species.
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