ROLE OF IMMUNUGLOBULIN IN GASTROINTESTINAL TRACT GROWTH OF CHOLESTEROL FED PIGLETS

Abstract

The gastrointestinal tract of a newborn piglet undergoes a remarkable increase in weight, length, protein, and DNA content when the piglet is suckled during the first day of life (Widdowson 1976). We have confirmed this observation and have observed that the increases are dependent upon the feeding of pig colostrum or colostral whey. When the piglet is given cow's milk formula or mature pig milk, gastrointestinal growth does not occur. The rate of intestinal growth is most evidence by 6 and 12 h of life. Histologic examination revals no increase in mitosis during this period, although protein is stored in the “lysosomes” of villar enterocytes of the suckled piglet. Because IgG is abundant in pig colostrum (up to 80% of why protein) we examined the function of IgG in mucosal growth and lysosomal storage observed histologically. Pig colostral whey was depleted of IgG by thiophilic column chromatography. When we fed the IgG-depleted colostral whey, we found reduced intestinal growth and no evidence for IgG transport or “lysosomal” storage. We conclude that IgG “lysosomal” storage accounts for a major proportion of the previously reported intestinal growth in the suckled piglet.