Cultured human lymphoblastoid cells exposed for short times to retinol and retinoic acid, undergo a time- and dose-dependent decrease in viability, accompanied by cell swelling. The presence of taurine (5-20 mM) and zinc (50-100 microM) protected cells from retinol-induced injury. Taurine 20 mM and zinc 100 microM added simultaneously abolished cell swelling and increased cell viability from 7 to 55%. Tocopherol (200 microM) was also effective in protecting these cells from retinol. The three compounds together afforded complete protection. The effects of retinol and of taurine, zinc or tocopherol seem to be unrelated to lipid peroxidation. A membrane stabilizer action is proposed as the mechanism underlying the protective effect of taurine and zinc or of tocopherol.