48: Studies on prepyloric lipase in premature and full-term newborns

Abstract

Lipolytic activity of pharyngeal origin with pH-optimum 5.4 has been found in esophageal and gastric aspirates of adult subjects (Hamosh et al.: J.clin.Invest.1975:55:908). We studied the gastric contents of seven premature and 11 full-term newborns to find out if lipolytic activity is present in the stomach. The samples were acid enough to exclude pancreatic lipase. As substrates we used H³-trioleate and ingested pasteurized milk, and the incubations were performed in 37°C at various pH in a 5%-albumin-buffer solution. Mono-, di-, triglycerides and FFA were separated by TLC. Four out of seven premature and all full-term newborns had clear lipolytic activity in the stomach shortly after birth, starting in the former group from the gestational age of 34 weeks. The lipase activity differed from pancreatic lipase by lower pH-optimum and acid-resistance. A lipase activity of this kind was also shown in a gastric sample of one infant with pyloric stenosis, and in a sample from the upper segment of esophagus of a newborn with esophageal atresia. Our preliminary results suggest that lipase activity in gastric contents appears already in newborns and even in prematures with gestational age over 33 weeks, and that the lipase involved differs from pancreatic lipase. Some evidence is given for the origin of the lipase from the uppermost gastrointestinal tract.

Grants: Ministry of Education, Finnish Academy, Jahnsson Foundation.