The effects of ruminant whey and its purified fractions on neutrophil
chemotaxis and superoxide production in sheep were studied. Both colostral
and milk whey were found to inhibit chemotaxis regardless of whether they
autologous or homologous, but the inhibitory effects were abolished by
neutrophils with culture medium before their use in the chemotaxis assay.
whey and milk whey also inhibited the chemotactic activity of zymosan-activated
serum. Whey fractions of various degrees of purity such as lactoferrin,
lacto-peroxidase, lactoferrin–lactoperoxidase, α-lactalbumin,
bovine serum albumin and
whey protein concentrate were then studied. While none of these proteins
any effects on chemotaxis, lactoferrin–lactoperoxidase
and whey protein concentrate
were found to have an enhancing effect on superoxide production in a
dose-dependent manner. Our results provide information on the modulatory
ruminant milk proteins in inflammatory responses and warrant future investigation.