The mitogenic effects of methyl sterculate on aortic smooth muscle cells.

Cyclopropenoid compounds are derived from naturally occurring C19 long chain fatty acids which have been shown to increase mitosis in rat hepatocytes, to elevate serum cholesterol and to enhance atherosclerosis in hens. In order to study the direct effects of sterculi acid triglyceride on smooth muscle proliferation, sterculic acid triglyceride in Sterculia foetida seed oil extract was added to tissue culture media in concentrations of 2 x 10(-6) to 2 x 10(-3)mg/ml and tested on primary as well as subcultures of rabbit aorta smooth muscle cells. In stationary primary rabbit aortic smooth muscle cell cultures the outgrowth of explants treated with Sterculia foetida seed extract increased in diameter. This response was similar to the increase of cultures treated with hyperlipemic serum (which has been shown to stimulate smooth muscle cell proliferation in previous studies in this laboratory). Using autoradiography following a (3H) thymidine pulse, the percentage of labeled cells was increased in the sterculic acid triglyceride treated groups, as compared to controls. In trypsinized, subcultured rabbit aortic smooth muscle cells, Sterculia foetida seed oil extract resulted in an increased incorporation of (3H) thymidine per milligram of protein. These results, indicating increased cell proliferation, were significant at p less than 0.05.