Insulin inhibits apolipoprotein B secretion in isolated human hepatocytes.
The effect of insulin on apolipoprotein (apo) B secretion was investigated in human hepatocytes. Freshly isolated hepatocytes, prepared by collagenase dispersion of liver specimens, were incubated in serum-free media in the absence and presence of 100 nmol/L insulin for 2 hours. The media was then assayed for apo B content by radioimmunoassay. In hepatocytes incubated without insulin, the secretion of apo B (relative to human low-density lipoprotein [LDL]) was 125 +/- 37 ng/10(6) cells/2 hours. In the presence of insulin, apo B secretion was reduced to 83 +/- 29 ng/10(6) cells/2 hours (34% inhibition, P less than .05). These results using human hepatocytes are consistent with previous data from our laboratory describing insulin-dependent inhibition of apo B secretion in primary cultures of rat hepatocytes and studies by others employing the human-derived hepatoma cell line, Hep G2. We conclude that human hepatic apo B secretion is under insulin control. The role of more chronic insulin exposure requires further investigation.
Salhanick
A I
AI
Department of Medicine, University of Rochester School of Medicine and Dentistry, NY 14642.
Schwartz
S I
SI
Amatruda
J M
JM
D001055:Apolipoproteins B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002452:Cell Count; D002469:Cell Separation; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D008079:Lipoproteins, VLDL / Q000378:metabolism; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D011863:Radioimmunoassay
D001055:Apolipoproteins B; D007328:Insulin; D008079:Lipoproteins, VLDL