In Vitro Evaluation of Hypotaurine Activity on Oxidized LDL
Recent reports on the antioxidant activity of hypotaurine indicate that it behaves as a hydroxyl radical scavenger7. In vitro experiments have shown excellent reactivity with ·OH and HOCl based on rate constants calculated for these reactions2. Cystamine-α-disulfone has been proposed as a product of the radical reaction12, as demonstrated by the isolation of this compound following an in vitro reaction of hypotaurine with Fenton’s reagent8. Notably cystamine-α-disulfone has been also isolated from male sexual tissues8. Hypotaurine affects the initiation, propagation and termination phases of lipid peroxidation15. In a recent review9 the antioxidant role of hypotaurine in the regenerating liver and male reproductive system, tissues in which hypotaurine is present in mM concentrations, has been discussed. In other tissues hypotaurine is present in such a minute amount (micromolar or less) as to cast doubts about its real capacity to act as an in vivo antioxidant. Target molecules for possible oxidation by highly reactive oxygen species (ROS, reactive oxygen species) are, among others, membrane lipids, protein structures and nucleic acids. A general protective effect of hypotaurine on membrane lipid structure is likely, in view of the protective action of hypotaurine on sperm motility1 and capacitation11.
KeywordsCaffeic Acid Male Reproductive System Conjugate Diene Formation Excellent Reactivity Membrane Lipid Structure
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- 4.Beuge, J.A and Aust, S.D., 1978, Microsomal lipid peroxidation, in Methods Enzymol. “Biomembranes”, Fleischer, S. and Packer, L., eds., 52:308.Google Scholar
- 7.Fellman, J.H. and Roth, E.S., 1985, The biological oxidation of hypotaurine to taurine: hypotaurine as an antioxidant, in Progr. Clin. Biol. Res. “Taurine: Biological actions and clinical Perspectives”, Oja, S.S., Ahtee, L., Kontro, P., and Paasonen, M.K., eds., Alan R. Liss, Inc., New York, vol. 179, pp. 71–82.Google Scholar
- 8.Fellman, J.H., Green, T.R., and Eicher, A.L., 1987, The oxidation of hypotaurine to taurine: bis-aminoethyl-α-disulfone, a metabolic intermediate in mammalian tissue, in Adv. Exp. Med. Biol. “The Biology of Taurine: Methods and Mechanism”, Huxtable, R.J., Franconi, F., and Giotti, A., eds., Plenum Press, New York, Vol. 217, pp. 39–48.Google Scholar
- 9.Huxtable, R.J., 1992, Physiological actions of taurine, Physiol. Reviews, 72:101–163.Google Scholar
- 10.Lindgren, F.T., 1975, Preparative ultracentrifugal laboratory procedures and suggestions for lipoprotein analysis, in: “Analysis of lipids and lipoproteins”, Perkins E.G., ed., AOCS, Campaign 111., pp. 204–224.Google Scholar
- 11.Meizel, S., Lui, C.W., Working, P.K., and Mrsny, R.J., 1980, Taurine and hypotaurine: their effects on motility, capacitation and the acrosome reaction of hamster sperm in vitro and their presence in sperm and reproductive tract fluids of several mammals, Dev. Growth Differ., 22:483–494.CrossRefGoogle Scholar
- 12.Ricci, G., Duprè, S., Federici, G., Spoto, G., Matarese, R.M., and Cavallini, D., 1978, Oxidation of hypotaurine to taurine by ultraviolet irradiation, Physiol Chem. & Phys., 10:435–441.Google Scholar