Intestinal Calcium Loss in Infant Rats

Abstract

Segments of the jejunum and ileum of 14-15 day old and 42 day old rats were perfused in situ with isotonic or hypertonic Ca free solutions. There was net secretion of Ca in all segments perfused. Rates of net secretion of Ca were several fold and significantly greater in segments of the 14 to 15 day old than in corresponding segments of the 42 day old rats. In the 14 to 15 day old rats net secretion of Ca was similar in jejunal and ileal segments, while in the 42 day old rats net secretion was 2-fold greater in the ileal than jejunal segments. Perfusion of the hypertonic solution almost doubled net secretion of Ca in the jejunal segments at both ages, but had no effect on rate secretion of Ca in the ileal segments. Infants are more prone to lose Ca into the lumen of the intestine than adults, especially during episodes of osmotic diarrhea when oral intake is restricted acutely.