XANTHINE OXIDOREDUCTASE FORMS IN TISSUES OF JAPANESE-QUAIL

The Japanese quail tissues - liver, kidney and pancreas were analysed for the presence of forms of xanthine oxidoreductase utilised cofactor s NAD+, molecular oxygen or artificial acceptor - methylene blue, as w ell as for the validity of correlation between enzymatic activity and diet protein content. Four groups of animals with the experimental die ts, the formulae of which are given in Tab. I, and control group with a commercial mash were fed for ten days. For enzyme preparation, the r ough purification of cytoplasmic fraction with subsequent dialysis was used. The xanthine oxidoreductase utilised NAD+ (XOR-NAD) was detecte d in all examined tissues (Fig. 1), whereby the correlation of enzymat ic activity with diet protein content was shown only in liver, accordi ng our previous findings (Jankela;1978; Baranovska and Gazo, 1990). Th e values in liver and pancreas of animals fed a commercial mash were s omewhat out of the range of linearity, probably because of the presenc e of nonprotein substances in mash, which affected the XOR activity in these organs (Jankela , 1992). The XOR utilised 02 (Fig. 2) was only detected in liver and kidney with certain activity in animals fed free protein diet. The percentage of this enzyme form was below 18 % of th e total activity (Fig. 5). The xanthine oxidoreductase utilised methyl ene blue (XOR-MM) was detected in liver, kidney and pancreas (Fig. 3). The correlation of enzymatic activity with diet protein content was l inear in liver and kidney. The percentage of XOR-MM activity was very high, it amounted to 55 % of the total activity (Fig. 4). The joint de termination of both forms of XOR (XOR-NAD+ and XOR-MM) may be a valuab le tool for utilization of XOR activity as a marker of the nutritional value of feed.