Abstract
The very low density lipoprotein (VLDL) receptor is a member of the LDL receptor family.
As opposed to the LDL receptor, the VLDL receptor is expressed primarily in muscle
and adipose tissue. Although the VLDL receptor is capable of binding lipoproteins,
its functional role is still unclear. Previous studies found that VLDL receptor expression
is unaffected by fasting in the rat. The current studies examined whether VLDL receptor
expression is altered with fasting in the mouse. Balb/c mice were fasted for periods
up to 48 hours, killed, hearts and epididymal fat obtained, and total membranes prepared.
To detect the VLDL receptor a portion of the rat VLDL receptor was expressed as a
bacterial fusion protein, purified and used to immunize rabbits. The antibodies raised
specifically recognized intact VLDL receptor. When cardiac membranes were immunoblotted,
VLDL receptor expression increased progressively with fasting, doubling at 36 hours.
In contrast, VLDL receptor expression decreased progressively with fasting in membranes
from epididymal fat, being reduced 70% by 48 hours. Thus, VLDL receptor expression
appears to be regulated in mouse heart and fat by nutritional perturbation, supporting
a potential role for the VLDL receptor in the delivery of triglycerides/fatty acids
as fuel.
Key words
VLDL Receptor - Fusion Protein - Recombinant Protein - Expression in Bacteria - Immunoblot
- Fasting - Mouse - Adipose Tissue - Heart
