SUCCINATE TETRAZOLIUM REDUCTASE ACTIVITY IN THE DEVELOPING RAT THYMUS

Abstract
Postnatal development of the rat thymus was studied. Succinate tetrazolium reductase activity, expressed as μg formazan per gram of fresh thymus tissue, remained unchanged from the 3rd to the 294th day after birth. The activity of the enzyme was also found to be unchanged histochemically during the postnatal life of the rat. The thymus attained its maximum weight, about 500 mg, at the age of 50 days. Thereafter it decreased steadily, amounting to some 175 mg in rats about 250 days of age.