Reduction in serum lecithin:cholesterol acyltransferase activity in natural cases of pneumonia in calves.

In experimental calf pneumonia induced by inoculations of Pasteurella haemolytica or bovine herpesvirus-1, lipoprotein lipid concentrations and lecithin:cholesterol acyltransferase (LCAT) activity decrease. The purpose of this study was to examine whether similar changes in lipoproteins occur in natural cases of calf pneumonia. When monitored in a time-course study, the activity of LCAT, and the concentrations of free cholesterol, cholesteryl esters, phospholipids and triglycerides were steadily decreased. No significant decreases in LCAT activity or lipid concentrations were detected in sera from cows with mastitis. These results, coupled with the previous findings on experimental calf pneumonia, indicate that, while decreases in LCAT activity and the LCAT-related lipid concentrations are involved in the pathogenesis of calf pneumonia, this is not the case for all inflammatory diseases.