DEVELOPMENT OF LIPOLYTIC-ACTIVITY IN GASTRIC ASPIRATES FROM PREMATURE-INFANTS

Neonates, having little or no pancreatic lipase, would have a compromised ability to digest lipids if not for lingual and gastric lipases. To document the postnatal developmental profile of preduodenal lipase activity, 350 premature infants who were at various gestational ages and who had an orogastric tube had their gastric aspirates collected. Two hundred one infants had their gastric aspirates collected within 12 h after delivery. Serial collections were performed in 25 infants at various postnatal ages. Gastric aspirates collected from premature infants had a pH activity profile similar to that of lingual and gastric lipase but different from that of pancreatic lipase, indicating that their origin was from the tongue and/or stomach. Lipolytic activity and pH of these aspirates were quite variable, but no correlation was found between pH and enzyme activity. At birth, lipase activity was lower in the younger infants (less-than-or-equal-to 26 weeks, n = 13). It increased to a peak at 30-32 weeks of gestational age and then declined to a lower level at term (greater-than-or-equal-to 40 weeks, n = 40). Postnatally, a composite plot of the serially collected aspirates also showed a predominant peak at 28-33 weeks of age. Comparison among siblings in twins (n = 12 pairs) and triplets (n = 3) showed great variations in their lipolytic activities, suggesting that the hereditary factor is not a major determinant. Various combinations of antibiotic medications (ampicillin, cefotaxime, gentamicin, and vancomycin) and drugs (dexamethasone, heparin, furosemide, phenobarbital, albumin, and vitamin K) apparently had no effect on the level and development of gastric lipolytic activities. Continuous as opposed to intermittent parenteral alimentation with Intralipid, a soybean oil emulsion for intravenous use, appeared to promote the development of lipase activities in the gastric aspirates postnatally.