The Effect of Sulfhdryl Oxidation on the Morphology of Immature Hamster Epididymal Spermatozoa Induced to Acquire Motility in Vitro1

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 degrees towards the tail. In addition, we demonstrated that sperm flagellar bending did not occur 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 content of 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 spermatozoa treated 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 development of motility during sperm epididymal maturation in vivo.

Characterization of the motility of maturing rat spermatozoa by computer-aided objective measurement

“…Another factor, forward motility protein (FMP), was implicated in the change in caput epididymal spermatozoan motility from a circling to a progressive motion in bulls (Acott et al, 1983) and hamsters (Kann & Serres, 1980;Serres & Kann, 1984) in vitro. In the hamster, retroflexion of the head brought about by such motility induction may be controlled by sulfydryl oxidation (Cornwall et al, 1986(Cornwall et al, , 1988.…”

Acquisition of volume regulatory response of sperm upon maturation in the epididymis and the role of the cytoplasmic droplet

“…Indirect evidence that K ϩ is involved in sperm volume regulation comes from the nonosmotic interpretation of hamster caput sperm angulation discussed in a series of articles by Cornwall et al (1986Cornwall et al ( , 1988 and Cornwall and Chang (1990). They observed angulation at the neck or midpiece of caput sperm, but only when they were stimulated to motility by theophylline and hamster caudal epididymidal fluid and they ruled out an osmotic origin since the medium used was 387 mmol/kg.…”

Epididymis seleno-independent glutathione peroxidase 5 maintains sperm DNA integrity in mice

“…In recent years, it has became clearer that ROS (especially hydrogen peroxide) exert dual and opposite actions on sperm cells (2,15). Basically, a certain level of ROS is necessary for disulfide bridging events that concern not only the sperm nucleus but also other protein-protein interactions on sperm plasma membrane, midpiece, and flagella (16)(17)(18)(19)(20)(21)(22)(23)(24)(25). Hydrogen peroxide was also identified as a key signal transduction effector of tyrosine phosphorylation events that trigger sperm capacitation (26,27) and ultimately acrosome reaction (reviewed in ref.…”