Regulation of cholesteryl ester transfer activity in adipose
tissue: a comparison between hamster and rat species.
Shen, Garry X., and Aubie Angel.
Departments of Internal Medicine and Physiology, The University of
Manitoba, Winnipeg, Manitoba R3E 3J7, Canada
APStracts 2:0045E, 1995.
The present study demonstrates cholesteryl ester transfer activity
(CETA) in cultured hamster and rat adipose tissue. Cultured hamster
and rat adipose tissue fragments released CETA into the conditioned
medium and this was associated with a reciprocal decrease in adipose
tissue CETA. Regional variations in adipose CETA was observed. The
levels of CETA released from cultured hamster and rat adipocytes were
higher than those from adipose tissue fragments. In hamsters but not
in rats the secretion of CETA from cultured adipose tissue was
increased by insulin and inhibited by EDTA in a dose dependent
fashion. Monoclonal antibodies against human cholesteryl ester
transfer protein (CETP) inhibited the CETA secreted from hamster
adipose tissue but not that from rat adipose tissue. Fasting for 24 h
and a cholesterol/saturated fat-rich diet increased adipose CETA in
hamsters and rats, and this was associated with an elevation of
plasma CETA only in hamsters. This supports the view that in
hamsters, adipose CETA has both in situ and intravascular functions
while in rat the role of adipose CETA is restricted to tissue
-specific functions. Hamster CETP may differ from rat adipose
associated CETA in the structure of the active site and the
regulatory mechanism for its secretion.
Received 7 September 1994; accepted in final form 21 February
1995.
APS Manuscript Number E362-4.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 10 March 1995.