Abstract
When sperm of Strongylocentrotus purpuratus or Lytechinus pictus are diluted into seawater, motility is initiated; and when exposed to egg jelly, an acrosome reaction is induced. In the presence of a variety of structurally different metal chelators (0.1-1 mM EDTA, EGTA, phenanthroline, dipyridyl, cysteine, or dithiothreitol), motility initiation is delayed and the acrosome reaction is inhibited. Of the metals detected in the sperm of these two species, very low levels of Zn+2 (0.1 microM free Zn+2) uniquely prevent this chelator inhibition. L. pictus sperm concentrate 65Zn+2 from seawater, and EDTA removes 50% of the accumulated 65Zn+2 by 5 min. Since both sperm motility and acrosome reactions are in part regulated by intracellular pH (pHi), the effect of chelators on the sperm pHi was examined by using the fluorescent pH sensitive probe, 9-aminoacridine, EDTA depresses sperm pHi in both species, and 0.1 microM free Zn+2 reverses this pHi depression. When sperm are diluted into media that contain chelators, both NH4Cl and monensin (a Na+/H+ ionophore) increase the sperm pHi and reverse the chelator inhibition of sperm motility and acrosome reactions. The results of this study are consistent with the involvement of a trace metal (probably zinc) in the pHi regulation of sea urchin sperm and indicate a likely mechanism for the previously observed effects of chelators on sperm motility and acrosome reactions.
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- Alitalo K., Keski-Oja J., Bornstein P. Effects of Zn2+ ions on protein phosphorylation in epithelial cell membranes. J Cell Physiol. 1983 Jun;115(3):305–312. doi: 10.1002/jcp.1041150314. [DOI] [PubMed] [Google Scholar]
- Christen R., Schackmann R. W., Shapiro B. M. Elevation of the intracellular pH activates respiration and motility of sperm of the sea urchin, Strongylocentrotus purpuratus. J Biol Chem. 1982 Dec 25;257(24):14881–14890. [PubMed] [Google Scholar]
- Delgado N. M., Huacuja L., Pancardo R. M., Rosado A. Modification on human sperm metabolism by the induced release of intracellular zinc. Life Sci. 1975 May 1;16(9):1483–1488. doi: 10.1016/0024-3205(75)90046-6. [DOI] [PubMed] [Google Scholar]
- Johnson C. H., Clapper D. L., Winkler M. M., Lee H. C., Epel D. A volatile inhibitor immobilizes sea urchin sperm in semen by depressing the intracellular pH. Dev Biol. 1983 Aug;98(2):493–501. doi: 10.1016/0012-1606(83)90378-0. [DOI] [PubMed] [Google Scholar]
- Johnson C. H., Epel D. Heavy metal chelators prolong motility and viability of sea urchin sperm by inhibiting spontaneous acrosome reactions. J Exp Zool. 1983 Jun;226(3):431–440. doi: 10.1002/jez.1402260314. [DOI] [PubMed] [Google Scholar]
- Kopf G. S., Garbers D. L. Correlation between sea urchin sperm respiratory rates and cyclic AMP concentrations as a function of cell dilution. Biol Reprod. 1978 Mar;18(2):229–233. doi: 10.1095/biolreprod18.2.229. [DOI] [PubMed] [Google Scholar]
- Lee H. C., Johnson C., Epel D. Changes in internal pH associated with initiation of motility and acrosome reaction of sea urchin sperm. Dev Biol. 1983 Jan;95(1):31–45. doi: 10.1016/0012-1606(83)90004-0. [DOI] [PubMed] [Google Scholar]
- Lindholmer C. Toxicity of zinc ions to human spermatozoa and the influence of albumin. Andrologia. 1974;6(1):7–16. doi: 10.1111/j.1439-0272.1974.tb01583.x. [DOI] [PubMed] [Google Scholar]
- Meizel S., Lui C. W. Evidence for the role of a trypsin-like enzyme in the hamster sperm acrosome reaction. J Exp Zool. 1976 Jan;195(1):137–144. doi: 10.1002/jez.1401950113. [DOI] [PubMed] [Google Scholar]
- Morisawa M. Heavy metals and spermatozoan motility. III conformational changes induced by divalent cations and by ATP in flagellar proteins. J Mechanochem Cell Motil. 1976;3(4):239–245. [PubMed] [Google Scholar]
- Morisawa M., Mori H. Heavy metals and spermatozoan motility. I. Distribution of iron, zinc and copper in sea urchin spermatozoa. Exp Cell Res. 1972 Feb;70(2):311–316. doi: 10.1016/0014-4827(72)90141-3. [DOI] [PubMed] [Google Scholar]
- Saito S., Bush I. M., Whitmore W. F., Jr Effects of certain metals and chelating agents on rat and dog epididymal spermatozoan motility. Fertil Steril. 1967 Jul-Aug;18(4):517–529. doi: 10.1016/s0015-0282(16)36370-1. [DOI] [PubMed] [Google Scholar]
- Santos-Sacchi J., Gordon M., Williams W. L. Potentiation of the cGMP-induced guinea pig acrosome reaction by zinc. J Exp Zool. 1980 Aug;213(2):289–291. doi: 10.1002/jez.1402130217. [DOI] [PubMed] [Google Scholar]
- Schackmann R. W., Christen R., Shapiro B. M. Membrane potential depolarization and increased intracellular pH accompany the acrosome reaction of sea urchin sperm. Proc Natl Acad Sci U S A. 1981 Oct;78(10):6066–6070. doi: 10.1073/pnas.78.10.6066. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schackmann R. W., Eddy E. M., Shapiro B. M. The acrosome reaction of Strongylocentrotus purpuratus sperm. Ion requirements and movements. Dev Biol. 1978 Aug;65(2):483–495. doi: 10.1016/0012-1606(78)90043-x. [DOI] [PubMed] [Google Scholar]
- Schackmann R. W., Shapiro B. M. A partial sequence of ionic changes associated with the acrosome reaction of Strongylocentrotus purpuratus. Dev Biol. 1981 Jan 15;81(1):145–154. doi: 10.1016/0012-1606(81)90357-2. [DOI] [PubMed] [Google Scholar]
- Swarup G., Garbers D. L. Phosphoprotein phosphatase activity of sea urchin spermatozoa. Biol Reprod. 1982 Jun;26(5):953–960. doi: 10.1095/biolreprod26.5.953. [DOI] [PubMed] [Google Scholar]
- WHITE I. G. The toxicity of heavy metals to mammalian spermatozoa. Aust J Exp Biol Med Sci. 1955 Jun;33(3):359–366. doi: 10.1038/icb.1955.36. [DOI] [PubMed] [Google Scholar]
- Ward G. E., Vacquier V. D. Dephosphorylation of a major sperm membrane protein is induced by egg jelly during sea urchin fertilization. Proc Natl Acad Sci U S A. 1983 Sep;80(18):5578–5582. doi: 10.1073/pnas.80.18.5578. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Young L. G., Nelson L. The effects of heavy metal ions on the motility of sea urchin spermatozoa. Biol Bull. 1974 Aug;147(1):236–246. doi: 10.2307/1540581. [DOI] [PubMed] [Google Scholar]
