INFLUENCE OF WHEY AND PURIFIED WHEY PROTEINS ON NEUTROPHIL FUNCTIONS IN SHEEP

The effects of ruminant whey and its purified fractions on neutrophil chemotaxis and superoxide production in sheep were studied. Both colos tral whey and milk whey were found to inhibit chemotaxis regardless of whether they were autologous or homologous, but the inhibitory effect s were abolished by washing neutrophils with culture medium before the ir use in the chemotaxis assay. Colostral whey and milk whey also inhi bited the chemotactic activity of zymosan-activated serum. Whey fracti ons of various degrees of purity such as lactoferrin, lactob peroxidas e, lactoferrin-lactoperoxidase, alpha-lactalbumin, bovine serum albumi n and whey protein concentrate were then studied. While none of these proteins showed any effects on chemotaxis, lactoferrin-lactoperoxidase and whey protein concentrate were found to have an enhancing effect o n superoxide production in a dose-dependent manner. Our results provid e information on the modulatory role of ruminant milk proteins in infl ammatory responses and warrant future investigation.