ASP stimulates glucose transport in cultured human adipocytes.
OBJECTIVE
The purpose of the present study was to examine the effect of Acylation Stimulating Protein (ASP) on glucose transport in cultured subcutaneous adipocytes.


METHODS
Subcutaneous adipose tissue was obtained from non-obese, healthy females (18-32 y old) undergoing mammoplasty reduction. Preadipocytes were isolated and differentiated into adipocytes.


METHODS
Following the exposure of preadipocytes and adipocytes to ASP or insulin, glucose transport was assessed as [3H] 2-deoxy glucose uptake. The measurements were normalised per total cell protein.


RESULTS
ASP increases specific membrane glucose transport in both preadipocytes and adipocytes in a time and concentration dependent manner. Stimulation in both cell types is rapid (within minutes), reaching a maximal effect between 1 and 4 h. However, after 24 h exposure to ASP, there is a downregulation in the response. The ASP response is greater following differentiation of preadipocytes to adipocytes and is compared to that of insulin. Dose response studies demonstrated a five-fold greater sensitivity of adipocytes (half-maximal concentration of ASP on adipocytes = 0.5 microM, preadipocytes = 2.3 microM).


CONCLUSIONS
These results demonstrate that ASP not only stimulates triglyceride synthesis, but also glucose transport in differentiated human adipocytes and is consistent with a physiologically important role for ASP in postprandial energy storage.
Maslowska
M
M
McGill Unit for the Prevention of Cardiovascular Disease, Royal Victoria Hospital, McGill University, Montreal, Quebec, Canada.
Sniderman
A D
AD
Germinario
R
R
Cianflone
K
K
D017667:Adipocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D000328:Adult; D001692:Biological Transport / Q000187:drug effects; D001798:Blood Proteins / Q000494:pharmacology*; D001940:Breast / Q000166:cytology / Q000473:pathology; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D015926:Complement C3a / Q000031:analogs & derivatives*; D003847:Deoxyglucose / Q000032:analysis / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D005260:Female; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D013997:Time Factors; D014316:Tritium
D001798:Blood Proteins; D007328:Insulin; C044541:complement C3a, des-Arg-(77)-; D014316:Tritium; D015926:Complement C3a; D003847:Deoxyglucose