Abstract
We report that secretion of very low density lipoprotein (VLDL) from the liver is regulated by the central nervous system. To elucidate the mechanism of regulation, we studied the effects of various neural factors on VLDL secretion from primary cultured rat hepatocytes.
Primary cultured rat hepatocytes were prepared from the liver of male Wistar rats (body weight 250g) by the collagenase method. Lipid fractions in these cells were labeled by preincubation with C14-acetate or C14-palmitate. VLDL secretion was measured as the amount of phosphotungstateprecipitable radioactivity in the medium, after incubation of cells in the presence of catecholamines or acetylcholine.
Thirty percent of VLDL secretion from hepatocytes was suppressed by the addition of epinephrine or norepinephrine, but not by acetylcholine or isoproterenol. The suppressive effect of epinephrine was not observed when the cells were preincubated with phenoxybenzamine.
The results suggest that VLDL secretion from hepatocytes is regulated by sympathetic nervees through α-adrenergic receptors.
