Relation between Toxicity of Cryoprotectant DMSO and Its Concentration in Several Fish Embryos

抄録

Although dimethyl sulfoxide (DMSO) has been often used in cryopreservation of f sh embryo as an effective cryoprotectant, its maximum concentration in terms of its toxicity wasobscure. When the embryos of several fish species, medaka, pejerrey, rainbow trout and carp, were immersed in solutions of various DMSO concentrations, the amounts of DMSO penetrating into the embryos were measured by HPLC and simultaneously their mortalities were determined from observation undermicroscope. From the uptake curves of DMSO, the permeability coefficients of DMSO to the eggmembrane were estimated to be 0.13 to 1.09×10-4cm/sec. Furthermore, the relations of accumulative mortality v. s. DMSO concentration in embryos were well expressed by a cumulative normal distribution function, and the averageDMSO lethal concentration of each embryo, giving a cumulative mortality of 50%, and its variance were determined. It was concluded that the tolerance to DMSO becomes higher in the order of carp, rainbow trout, pejerrey, and medaka.