I. Murray et al., Acylation stimulating protein (ASP) deficiency alters postprandial and adipose tissue metabolism in male mice, J BIOL CHEM, 274(51), 1999, pp. 36219-36225
Acylation stimulating protein (ASP) is a potent stimulator of triglyceride
synthesis in adipocytes. In the present study, we have examined the effect
of an ASP functional knockout (ASP(-/-)) on lipid metabolism in male mice.
In both young (14 weeks) and older (26 weeks) mice there were marked delays
in postprandial triglyceride clearance (80% increase at 14 weeks and 120%
increase at 26 weeks versus wild type (+/+)). Postprandial nonesterified fa
tty acids were also increased in ASP(-/-) mice versus ASP(+/+) mice by 37%
(low fat 10% Kcal) and by 73% (high fat 40% Kcal) diets, although there wer
e no differences in fasting lipid levels. The ASP(-/-) mice had moderately
increased energy intake (16% +/- 2% p < 0.0001) and reduced feed efficiency
(33% increase in calories/g of body weight gained on low fat diet) versus
wild type, The ASP(-/-) mice also had modest changes in insulin/glucose met
abolism (30% to 40% decrease ill insulin glucose product), implying increas
ed insulin sensitivity. As well, there were decreases in leptin (29% shift
in leptin to body weight ratio) and up to a 26% decrease in specific adipos
e tissue depots versus the wild type mice on both low fat and high fat diet
s, These results demonstrate that ASP plays an important role in adipose ti
ssue metabolism and fat partitioning.