Butyrate morphological changes induced

Morphological changes were prevented in butyrate-treated HeLa cells by actinomycin D and cycloheximide (2,8,13). After removal of butyrate, the cells reverted to a normal morphology over a 24 h time course (2,8,12,13). When butyrate-treated cells were detached from the cuTture dishes with trypsin, they assumed a spherical shape and, when replated in the absence of butyrate, their neurite-like processes transiently re-extended (13). This re-extension was blocked when cycloheximide but not the calcium ionophore was included during the initial exposure of the cells to butyrate (13). Process formation, however, did resume in the presence of cycloheximide (1 3). These results were interpreted as indicating that the fatty acid induces a protein(s) required for process formation which can accumulate in the absence of processing and promote processing in the absence of inducer (13). 

Although these results are difficult to interpret in molecular terms, they provide a basis for further research. The morphological changes brought about from these mixing experiments suggest that the TPA-induced increases in glycosyltransferase activity are the result of a different process than those induced by RA or butyrate (manuscript in preparation). 

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