Lipoprotein lipase in human milk: compartmentalization and effect of fasting, insulin, and glucose

The object of this study was to investigate the effect of maternal metabolic state on the activity of lipoprotein lipase (LPL) in human milk. Although the total LPL activity in milk was not significantly affected by up to three cycles of freezing and thawing, the amount of LPL associated with the cr...

Full description

Saved in:
Bibliographic Details
Published in:Journal of lipid research 1991-02, Vol.32 (2), p.251-257
Main Authors: Neville, MC, Waxman, LJ, Jensen, D, Eckel, RH
Format: Article
Language:English
Subjects:
ACTIVIDAD ENZIMATICA
ACTIVITE ENZYMATIQUE
Adult
Analytical, structural and metabolic biochemistry
Biological and medical sciences
Enzyme Stability
Enzymes and enzyme inhibitors
Fasting
Female
Freezing
Fundamental and applied biological sciences. Psychology
GLUCOSA
GLUCOSE
Glucose - physiology
Humans
Hydrolases
INANICION
INANITION
Insulin - physiology
INSULINA
INSULINE
Kinetics
LAIT HUMAIN
LECHE HUMANA
Lipoprotein Lipase - metabolism
Milk, Human - enzymology
Temperature
TRIACILGLICEROL LIPASA
TRIACYLGLYCEROL LIPASE
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The object of this study was to investigate the effect of maternal metabolic state on the activity of lipoprotein lipase (LPL) in human milk. Although the total LPL activity in milk was not significantly affected by up to three cycles of freezing and thawing, the amount of LPL associated with the cream fraction of the milk increased from an average of less than 10% to about 70% after this treatment. The enzyme was relatively stable when the milk was stored on ice, losing activity at a rate of about 1% per hour. At 37 degrees C degradation was more rapid, about 7% per hour. When LPL activity was measured in samples taken at hourly intervals by breast pump, using oxytocin to achieve a complete letdown at each pumping, activity was found to double from the first to the third pumping. Thereafter the activity was stable under fasting conditions. Hyperglycemic and euglycemic, hyperinsulinemic glucose clamp protocols were used to evaluate the effects of glucose and insulin. Both high plasma glucose and high plasma insulin in the presence of normal glucose significantly increased LPL activity within 4 hours. We conclude that, like adipose, tissue LPL, mammary LPL is regulated by plasma insulin.
ISSN:0022-2275
1539-7262
DOI:10.1016/S0022-2275(20)42086-3