PLASMA SOMATOSTATIN AND CHOLECYSTOKININ LEVELS IN RESPONSE TO FEEDINGIN PRETERM INFANTS

Background: The functions of the gut are modulated by the autonomic ne rvous system and gut peptides, such as somatostatin and cholecystokini n, which have opposite functions. This study reports plasma somatostat in and cholecystokinin levels in response to feeding in preterm infant s. Methods: In 76 infants-gestational age 23 to 36 weeks, birth weight 460 to 2867 g-blood samples were taken on day 1 before the first meal in life, and 30 minutes after the end of the meal. Samples were again taken on days 3 and 4. The infants were fed human milk by nasogastric tube, by breast, or by battle. In 10 additional infants, (gestational age 27-36 weeks) who were studied at a median postnatal age of 15 day s, the response of the peptides to breast-feeding was compared with th at of tube-feeding. Plasma somatostatin and cholecystokinin were analy zed by specific radioimmunoassays. Results: On day 1, the median plasm a somatostatin level increased after feeding in small-for-gestational- age infants but not in appropriate-for-gestational-age infants. On day s 3 and 4, the somatostatin level decreased in infants with a gestatio nal age of 32 weeks or more. On day 1, plasma cholecystokinin levels i ncreased in infants with a gestational age of 32 weeks or more: The re sponse was more pronounced in small-for-gestational-age infants. On da ys 3 and 4, plasma cholecystokinin levels increased only in breast-fee ding infants. In the 10 infants fed by breast and by tube, plasma chol ecystokinin levels increased after breast-feeding and tended to increa se after tube-feeding. The plasma somatostatin levels were unaffected after feeding. Conclusions: Plasma somatostatin and cholecystokinin in creased after feeding in small-for-gestational-age infants on day 1. O n days 3 and 4, the responses to feeding seemed to be dependent on the infant's gestational age. Breast-feeding enhanced the release of chol ecystokinin but not that of somatostatin.