Abstract
Addition of hydrocortisone to medium with a well-balanced amino acid composition, such as Eagle's Minimum Essential Medium, inhibited the growth of HeLa cells. However, hydrocortisone had various effects when added to cells cultured in media in which only one amino acid was reduced. Its effect depended on the deficient amino acid: in media of low isoleucine, methionine or phenylalanine content it pro-moted cell growth, while in media of low lysine or histidine content it had no effect.
In medium containing a low level of methionine (Low Met Med), the free methionine content in the cells increased on addition of hydrocortisone. The incorporation of 35S-methionine into the acid-soluble fraction of these cells also increased on addition of hydrocortisone. Thus the growth promoting effect of hydrocortisone on cells cultured in Low Met Med may be dependent on increased absorption of limiting amino acid into cells.
