Comparison of liver peroxisomal enzyme activity changes during development of diploid and haploid anurans

In order to clarify the biochemical and physiological differences between diploid and haploid amphibians, activity changes in three peroxisomal enzymes found in the livers of diploid and haploid Rana rugosa were investigated at various stages of development using the spectrophotometric method. Gynogenetic haploids were produced by artificial fertilization of eggs with ultraviolet-irradiated sperm. In diploids, the total and specific activities of hydrogen peroxide destroying catalase began to show an increase at stage XXV (metamorphosis completion), attaining a maximum 1 month later, while total and specific activities of hydrogen peroxide forming D-amino acid oxidase and urate oxidase decreased, Haploids, on the other hand, showed only one-seventh to one-twelfth the total and specific catalase activity of diploids after stage XXV, while coral and specific oxidase activity increased. These results seem to indicate that the system for hydrogen peroxide detoxification develops abnormally in the liver of haploids at the time of metamorphosis completion, which probably results in considerable cell damage, leading to hepatic failure and eventual death.