Metabolism of free and esterified cholesterol and triterns or transformed cell lines. Primary cultured chick acylglycerol was compared in cultured neuronal cells, embryonic neuronal cells described by Pettman et a1 glial cells, and fibroblasts grown from chick embryos. [ 19791 are pure neuronal cells isolated without using Cellular contents of free and esterified cholesterol antimitogenic reagents and show differentiation during were comparable in these cells and triacylglycerol culture. We chose chick neuronal cells and also glial cells content in the neuronal cells was about 40% of that in as model systems to investigate cholesterol metabolism the other cell types. Cholesterol synthesis from of brain.
[3Hlacetate was high in all these cells and was not
Since it has been shown that the cholesterol in the affected by fetal calf serum in the culture medium. CNS is derived principally from synthesis in situ [Davi-Monensin, which has been shown to influence choles-son, 19701 rather than transport from blood [Pardridge terol metabolism through the inhibition of low-density and Mietus, 19801, low-density lipoprotein (LDL) receplipoprotein receptor recycling in human fibroblasts, tor-mediated control of cholesterol metabolism which did not induce profound effects on cholesterol metaboperates in many cell types olism in these cells. Higher incorporation of [3H] oleic Goldstein and Brown, 19771 may not function in neuronal acid into esterified cholesterol was observed in the tissues. In C6 glial cells and neuroblastoma cells, 3glial cells and fibroblasts when fetal calf serum was hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reremoved from the culture medium. Cellular content ductase is a rate-limiting enzyme in cholesterol biosynof the esterified cholesterol also increased in the glial thesis and is regulated by cholesterol bound to LDL cells under a serum-free arrangement. 25-Hydroxy- [Volpe and Hennessy, 19771. However, when mouse cholesterol induced higher incorporation of both spinal cord explants were incubated in a lipid-deficient C3HJacetic acid and [3H]oleic acid into esterifid chomedium, there was no increase in specific activity of lesterol in all of these cells. The results indicate that HMG-CoA reductase [Pleasure and Kim, 19761. Volpe the active metabolism of cholesterol found in cultured et a1 [ 19781 reported that cholesterol ester synthesis was chick neural cells and fibroblasts may not be regustimulated by LDL, presumably mediating increasing lated by an LDL receptor-mediated system and some acyl CoA:cholesterol acyltransferase (ACAT) activity in factors in fetal calf serum inhibit cellular accumula-C6 glioma cells, but no such stimulation was observed in tion of esterified cholesterol. neuroblastoma cells. Our first objective was to investi-