Effect of hypocholesterolemic drug AY9944 on cultured nervous tissue: morphologic and biochemical studies.
The effects of different concentrations of the hypocholesterolemic drug AY9944, an inhibitor of delta7-reductase, on organotypic cultures of fetal mouse spinal cord, were studied by light and electron microscopy. Exposure to 10(-6)M produced no observable changes. After 6 hours exposure to 10(-4)M, dense membrane-bound inclusions were occasionally observed in neurons. After 24 hours exposure to 10(-4)M, numerous cytoplasmic inclusions occurred in neurons, glia and macrophages. The form of these inclusions varied but were predominantly of two types; concentric, loosely-packed lamellae resembling membranous cytoplasmic bodies (MCB) of Tay-Sachs disease and irregular dense bodies. They were identical to those observed in our previous in vivo study. Prolonged exposure to the drug at 10(-4)M caused an increased number of inclusions in all cell types. Eventually the cultures degenerated. The number of inclusions increased for at least 38 days following a 2-5 day exposure to AY9944 at 10(-4)M. However, by 70 days, although inclusions persisted, the cultures were mostly astrocytic. In long-term cultures, in addition to these inclusions, curved or straight electron-dense paired profiles were seen in some cells, presumably macrophages. Biochemical analysis of cultures exposed to 10(-4)M revealed the continuous presence of delta7, 24-cholesta-diene-3beta-ol and 7-dehydrocholesterol even after the drug wa removed from the cultures. In our previous animal experiments, intracytoplasmic inclusions and abnormal sterols with a double bond at the 7 position disappeared quickly after discontinuation of the drug. Therefore, the results obtained in our present in vitro experiments are different in this regard from the in vivo studies of AY9944.
D002775:Cholestadienols / Q000378:metabolism; D002784:Cholesterol / Q000031:analogs & derivatives / Q000378:metabolism; D046508:Culture Techniques; D003510:Cyclohexanes / Q000494:pharmacology*; D002479:Inclusion Bodies; D009417:Nerve Tissue / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D001371:trans-1,4-Bis(2-chlorobenzaminomethyl)cyclohexane Dihydrochloride / Q000494:pharmacology*
D002775:Cholestadienols; D003510:Cyclohexanes; D001371:trans-1,4-Bis(2-chlorobenzaminomethyl)cyclohexane Dihydrochloride; D002784:Cholesterol