Independent Effects of Human Platelet Growth Factor and Hydrocortisone on Acetate Incorporation by GM-237 Human Fibroblasts

Summary

In studying the metabolic effects of human platelet growth factor (HPGF), cellular [1–¹⁴C]acetate incorporation was investigated among GM-237 human diploid fibroblasts. When cultured in 0.5% fetal calf serum, cells doubled in the presence of 18 ng/ml HPGF during 72 hours, and a 138.4% increase on a per cell basis in total [1–¹⁴C]-acetate incorporation was found. Seventy-eight percent of the label was in cell lipid. Pharmacological doses of hydrocortisone (HC) at 1–200 μg/ml had no effect on cell division in the presence or absence of HPGF. However, a 40–76% reduction in total [1–¹⁴C]-acetate incorporation was found when HC was present. When HPGF and HC were added to cells simultaneously, analysis of the data revealed that HPGF and HC acted independently. Thus, HPGF can cause GM-237 human diploid fibroblasts to increase exogenous acetate incorporation and its conversion into lipids in a manner circumventing modulation by HC.