The effect of sulfhdryl oxidation on the morphology of immature hamster epididymal spermatozoa induced to acquire motility in vitro

GA Cornwall, D Vindivich, S Tillman… - Biology of …, 1988 - academic.oup.com
GA Cornwall, D Vindivich, S Tillman, TSK Chang
Biology of reproduction, 1988academic.oup.com
Immotile spermatozoa from the caput epididymidis become progressively motile when
incubated in medium containing theophylline, seminal plasma, and albumin. We previously
reported that under these incubation conditions the spermatozoa induced to acquire motility
exhibited a marked flagellar angularity, with the sperm head or midpiece bent 90–180°
towards the tail. In addition, we demonstrated that sperm flagellar bending did notoccur
when the sulfhydryl oxidant diamide was added to the motility induction medium. In the …
Abstract
Immotile spermatozoa from the caput epididymidis become progressively motile when incubated in medium containing theophylline, seminal plasma, and albumin. We previously reported that under these incubation conditions the spermatozoa induced to acquire motility exhibited a marked flagellar angularity, with the sperm head or midpiece bent 90–180° towards the tail. In addition, we demonstrated that sperm flagellar bending did notoccur when the sulfhydryl oxidant diamide was added to the motility induction medium. In the present study, we examined further the Effect of sulfhydryl oxidation on the morphology and sulfhydryl contentof immature caput spermatozoa induced to acquire motility in vitro. We found that flagellar bending was prevented and sperm flagellar straightness was maintained in a dose-dependent manner by diamide. Moreover, flow cytometric analysis of caput sperm sulfhydryls using the sulfhydryl reagent monobromobimane (mBBr) revealed that 1) diamide oxidizes caput sperm sulfhydryls, and 2) less than 15% of the total reactive sperm sulfhydryls were oxidized at diamide concentrations capable of preventing sperm angulation. Sodium tetrathionate (NaTT), another sulfhydryl oxidant, and hamster cauda epididymal fluid (CEF) containing sulfhydryl oxidase enzyme activity also maintained flagellar straightness in induced caput spermatozoa and oxidized sperm sulfhydryls. The flagellar straightness in caput spermatozoatreated with sulfhydryl oxidants, however, was temporary; with extended incubation, diamide- or CEF-treated spermatozoa exhibited flagellar bending. Additional studies showed that the flagellar straightness observed in sulfhydryl-oxidized spermatozoa was sustained when nitrofurantoin, an inhibitor of glutathione reductase, was included in the induction medium. Flow cytometric analysis of nitrofurantoin-treated spermatozoa showed that nitrofurantoin maintained the sperm disulfides formed by diamide and prevented the reduction of sperm disulfides back to sulfhydryls. Taken together, these studies demonstrate the significance of sulfhydryl oxidation in maintaining the morphology of immature caput epididymal spermatozoa induced to acquire motility in vitro and suggest that sulfhydryl oxidation may be important in the developmentof motility during sperm epididymal maturation in vivo.
Oxford University Press