- 著者
-
Aoki Tsugutoshi
Arima Masataka
- 出版者
- Japanese Society of Gout and Nucleic Acid Metabolism
- 雑誌
- 尿酸 (ISSN:03884120)
- 巻号頁・発行日
- vol.1, no.1, pp.35-41, 1977
Measurement was made of HGPRT and APRT activities in erythrocytes for 15 cases of Lesch-Nyhan syndrome. As for the activity of HGPRT in 2 cases with Lesch-Nyhan syndrome, there appeared the enzyme activity when the substrates, concentrations of hypoxanthine and PRPP, were made to rise. The activity of HGPRT in erythrocytes of two cases at high concentration of hy poxanthine rose in a sigmoid curve when the concentration of PRPP was made to rise, whereupon the apparent Km stood at 9.2×10<SUP>-3</SUP> and 9.8×10<SUP>-3</SUP>. This apparent Km was about 30 times that of the control group. The Km to hypoxanthine was 1.8×10<SUP>-4</SUP> in both cases, which was about 10 times that of the control group. The activity of HGPRT in erythrocytes of other 13 cases showed no change.<BR>In 1970, Seegmiller et al. provided deficiency of HGPRT activity in erythrocytes of patients with Lesch-Nyhan syndrome (1).<BR>In 1971, Arnold et al. (2) and Rubin et al. (3) purified HGPRT enzyme protein in erythrocytes of normal adult males and prepared anti-HGPRT serum using rats or rabbits. It was made clear that HGPRT enzyme protein is present in erythrocytes of patients with Lesch-Nyhan syndrome since these erythrocytes al beit without enzyme activity, showed an absorption band to anti-HGPRT serum serum immunologically. HGPRT protein in erythrocytes of patients with Lesch-Nyhan syndrome was reported to be 140μg/ml erythrocytes, an amount equal to that in normal adult males (4,5).<BR>Recently, McDonald et al. (6) have reported a variant type of erythrocyte HGPRT enzyme in one case of Lesch-Nyhan syndrome. This is of great interest since there have been previous reports merely on cases in which the enzyme activity was defect in this syndrome.<BR>We have made measurement of erythrocytes HGPRT and APRT enzyme activities in 15 cases of Lesch-Nyhan syndrome. In two cases, a rise in HGPRT activity was demonstrated for variations in concentrations of hypoxanthine and PRPP, the substrates.<BR>In this paper mention will be made of the enzymatic study on erythrocytes HGPRT and APRT activities referring to these two cases.