20,25-Diazacholesterol, clofibric acid and 2,4-dichlorophenoxyacetic acid— All inducers of myotonia—Perturb the post-lanosterol sector of sterol biosynthesis in cultured chick embryo fibroblasts

When administered to mammals 20,25-diazacholesterol (DAC), clofibric acid (CA) and 2,4-dichlorophenoxyacetic acid (2,4-D) induce myotonia. DAC and CA also interfere with cholesterol metabolism. No such effect has hitherto been observed for 2,4-D and hence there was no support for there being a causal relationship between drug-induced myotonia and impaired cholesterol biosynthesis. Radiogas chromatographic methods are used in this paper to establish that all three agents cause intermediates between lanosterol and cholesterol to accumulate in cultured chick embryo fibroblasts. It is therefore feasible to examine further the possibility that perturbed sterol metabolism is a sufficient and necessary condition for experimentally induced myotonia.