PROPERTIES OF ACATALASIC CELLS GROWING IN VITRO

Acatalasia, a disease due to homozygosity for a Mendelian gene, is characterized by the absence of the enzyme catalase from the tissues of the human body. Red cells from heterozygotes have enzyme activities about one-half normal. In this paper, the development of cell lines from skin biopsies on an affected homozygote, a heterozygote, and eight control patients is described. The cell type is the euploid "fibroblast." It was found that acatalasic cells lacked the enzyme, even after growing for many months in a medium rich in catalase. The control lines all had mean catalase activities double or more that of the heterozygous line. Selection experiments, in which the growth of cells exposed for 20 minutes to varying concentrations of hydrogen peroxide was measured, did not provide a system for preferentially eliminating acatalasic cells. Certain other experiments bearing on the enzymatic defect in this disease were performed

Studies on the xanthine oxidase activity of mammalian cells

Xanthine oxidase in man is confined to but a few tissues and is absent from cultured cell strains. In rodents, however, the enzyme is more widely distributed among the tissues and can be demonstrated in most cell lines. Rodents possess the enzyme uricase and are therefore able to carry purine catabolism one step further than man. Preliminary results suggest that uricase is restricted to but a few rodent tissues and is absent from cultured rodent cells. Hence it may be that in each species only the final enzyme of purine catabolism is tissue restricted. In other experiments, mammalian cells were grown in the presence of compounds known to induce xanthine oxidase in a eukaryotic fungus (Aspergillus nidulans) . These compounds did not induce the enzyme in mammalian cells.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44184/1/10528_2004_Article_BF00487339.pd

The influence of progressive growth on the specific catalase activity of human diploid cell strains. I. Effect of cellular genotype: Homozygous strains

The specific catalase activity of human diploid cell strains increases with progressive growth of the culture, and falls again following subculture. Although the increase is small, it is readily demonstrable, and is exponential with time. The response of catalase activity to proggressive growth of the culture was studied in three abnormal human cell lines. A diploid cell strain, developed from a patient homozygous for the gene causing acatalasia I, had no detectable catalase activity throughout the life cycle of the culture. Another diploid cell strain, developed from a patient homozygous for the gene causing acatalasia II, had about 5% normal catalase activity, but the proportionate increase in specific activity as the culture grew was the same as for normal cells. Thus the mutation causing acatalasia II does not change the responsiveness of the cell in terms of catalase activity to progressive growth of the culture. The behavior of a heteroploid line was similar to that of the normal diploid strains, but when the growth of the heteroploid cultures reached a plateau, their population densities were four times higher than those of the diploid strains and they had about twice the specific catalase activity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/49863/1/1040710205_ftp.pd