Within-day variation of lipolytic activity in human milk.
Milk was collected from six mothers during their 8th wk of lactation to determine the diurnal variation of bile salt-stimulated lipase and serum-stimulated lipase. On the day of collection, one breast was completely emptied at 0600, 1000, 1400, 1800, and 2000 h. Activities of bile-stimulated lipase and serum-stimulated lipase in the milk were determined. Activity of bile-stimulated lipase was constant throughout the day, whereas serum-stimulated lipase activity varied significantly with time. Both activities differed significantly in milk from different women. Time of collection must be considered when measuring activity of serum-stimulated lipase but is not a major variable when measuring activity of bile-stimulated lipase in human milk. These results may be helpful when designing future studies involving these enzymes.
D001647:Bile Acids and Salts; D001769:Blood; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000032:analysis; D008049:Lipase / Q000032:analysis; D008066:Lipolysis; D008895:Milk, Human / Q000201:enzymology*
D001647:Bile Acids and Salts; D007527:Isoenzymes; D008049:Lipase