Glutathione reductase activity and flavin concentration in guinea-pig tissues

Glutathione reductase (GR) activity and flavin concentration were studied i n systemic tissues (brain, heart, lung, liver, spleen, stomach, pancreas, m uscle, kidney, testis) and blood components (erythrocytes and plasma) from male guinea-pigs. GR activity and the flavin concentration were high in kid ney and liver, and low in muscle. GR activity in erythrocytes was found in a range of tissues, but flavin concentration in erythrocytes was lower than in any tissues. GR was saturated with flavin adenine dinucleotide (FAD) in almost all tissues but not in muscle or erythrocytes.