RECONSTITUTION OF MASTITIC MILK BY ADDING BLOOD-PLASMA AND LEUKOCYTESINTO LOW CELL COUNT MILK

Milk from inflamed quarters is high in somatic cells, proteolytic acti vity and lysosomal enzyme activity. Addition of homologous blood plasm a and leukocytes into low cell count milk did not increase the plasmin activity, total proteolytic activity or N-acetyl-beta-D-glucosaminida se (NAGase) as anticipated, even if the reconstituted milk samples wer e stimulated by endotoxin or opsonized zymosan. Addition of urokinase activated the latent proteolytic system in plasma-supplemented milk. T he reactive sulfhydryls in milk samples with different treatments decr eased significantly after incubation, indicating the presence of an ox idative mechanism in milk leg, sulfhydryl oxidase). The high backgroun d resazurin reduction of fresh milk might be due, in part, to the cell ular activity of somatic cells. This study indicates that a more compl ex system including inflammatory mediators and complex cellular intera ctions is required for expression of plasmin-activator activity and fo r full activation of the proteolytic and lysosomal enzymes in mastitic milk.