Comparison of the Growth of Fibroblasts Under the Influence of 11β-Hydroxy and 11-Keto Corticosteroids

Abstract

Fibroblasts of Clone 929-L were incubated in the presence of various concentrations of corticosteroids and quantitative measurements of cell growth were made by means of an electronic cell counter. It was found that the 11β-OH corticosteroids, cortisol, 2-methylcortisol, prednisolone, and corticosterone markedly inhibited fibroblast proliferation, whereas the 11-keto compounds, cortisone, 2-methylcortisone, prednisone, and 11-dehydrocorticosterone allowed fibroblast growth equal to or greater than control levels. 11-Desoxy compounds, 11-desoxycortisol and 11-desoxycorticosterone, caused cellular proliferation midway between that caused by 11β-OH and 11-keto compounds. Metabolic studies with cortisol-l,2-3H and cortisone-4- 14C showed that there was no interconversion between cortisone and cortisol when these substances were incubated with actively metabolizing strain L fibroblasts in cell culture. Therefore, although fibroblasts in connective tissue have an active 11β-OH dehydrogenase system, tissue culture fibroblasts do not manifest this enzymatic activity. It is suggested that the presence of a ketone group at C-ll influences the biological effectiveness of the steroid molecule in stimulating fibroblastic cell growth. (Endocrinology78: 373, 1966)