Lysozyme turnover in the rat was studied with 125I-labeled rat lysozyme. It was found that plasma lysozyme has a rapid disappearance rate with a half-life of 75 min. The rate of synthesis was calculated at 3.4 μg/min per 100 g rat. This rate of synthesis was compared with figures from the literature for the turnover rate of neutrophilic granulocytes, and the data were consistent with the concept that disintegrating neutrophils are the main source of plasma lysozyme.
