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The influence of conditioned media and nonessential amino acid supplementation on the growth of cells in vitro
Author(s) -
Oellermann Rolf A.,
Miller Elsa M.
Publication year - 1969
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1040740310
Subject(s) - amino acid , serine , alanine , stimulation , chemistry , cell growth , in vitro , cell culture , biochemistry , biology , endocrinology , enzyme , genetics
The growth enhancing effect of media conditioned by cells from established lines (BHK and L60) is comparable to that of media conditioned by cells of primary origin (chick embryo). However, the properties of the conditioned media from these two systems show marked differences: the growth enhancing factors in the former are dialyzable and heat‐stable, in contrast to the non‐dialyzable and heat‐labile factors in the latter. Media conditioned for only four hours by BHK or L60 cells stimulated cell growth. Amino acid analyses revealed that non‐essential amino acids had appeared in these conditioned media. To verify this as the metabolic basis of conditioning by cells from established lines, media containing dialyzed serum were supplemented with each of six non‐essential amino acids, and assayed on BHK and L60 at various population densities. Serine was the most stimulatory and alanine the most inhibitory of the amino acids tested. Mixed supplementation of the medium showed that when low levels of alanine and serine were added simultaneously, cell growth was enhanced but any increase in the level of alanine required an increase in the level of serine also to achieve growth stimulation.