Inhibition of the proteinase activity in mastitic milk

Summary The antiproteolytic activity of selected proteinase inhibitors was studied in mastitic bovine milk and urokinase-activated normal milk using a caseolytic agar diffusion assay. The inhibition profiles of mastitic milk and urokinase-activated milk were compared with those of purified proteinases. The proteinase inhibition profile of mastitic milk did not resemble that of any of the pure proteinases, indicating a mixed type of proteinase system in mastitic milk. The trypanocidals diminazene (equivalent to Berenil®) and pentamidine (equivalent to Lomidine®), together with aprotinin (Trasylol®), showed most promise when considering possible applications in mastitis to break up the proteolytic cascade within the inflamed udder.