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Effects of cholera toxin and isobutylmethylxanthine on growth of human fibroblasts

Journal Article · · Am. J. Physiol.; (United States)
OSTI ID:6415479
Cholera toxin produced a dose-dependent decrease in the restimulation of G0/G1 traverse in density-arrested human fibroblasts but did not inhibit the stimulation of cells arrested in G0 after serum starvation at low density. In addition, cholera toxin did not inhibit the proliferation of sparse logarithmically growing human fibroblasts, even when low concentrations of the phosphodiesterase inhibitor isobutylmethylxanthine (IBMX) were also present. However, the final density to which sparse cells grew was limited by cholera toxin, when added either alone or together with low concentrations of IBMX. In contrast, high concentrations of the phosphodiesterase inhibitor alone produced a profound inhibition in the growth of sparse human fibrobasts. IBMX produced an inhibition both in the G1 and in the G2 phases of the cell cycle by a mechanism(s) that was not related to the magnitude of the increases in adenosine 3,5-cyclic monophosphate concentrations.
Research Organization:
Los Alamos National Lab., NM
DOE Contract Number:
W-7405-ENG-36
OSTI ID:
6415479
Journal Information:
Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 251:2; ISSN AJPHA
Country of Publication:
United States
Language:
English