The amino acid metabolism of differentiating skeletal myoblasts in vitro

THE AMINO ACID AND PROTEIN METABOLISM OF TISSUES CULTIVATED IN VITRO

“…Swim & Parker (1958a) have reported the preparation and storage of defined media in dry form as a means of obtaining reproducible mixtures in long-term experiments. In our hands (Lucy & Rinaldini, 1959), however, dried media prepared by freeze-drying have not been satisfactory, since it has been found that the amino acid content of the media decreases during storage. It is thought that this may result from the combination of amino acids and glucose by reactions similar to the non-enzymic browning reaction described by Richards (1956).…”

“…It has been found by us (Lucy & Rinaldini, 1959), in collaboration with Webb, that cells that had been freshly isolated from the pectoral muscle of the embryonic chick synthesized glutamic acid, aspartic acid, glycine, alanine, serine and proline from generally labelled glucose when cultivated in a natural medium. Harris & Jahnz (1958) have grown connective tissue cells from the hearts of 5-day-old rats in a medium composed of 50% bovine serum and 50% Hanks's saline, with 0-001 M cysteine hydrochloride.…”

“…Furthermore, phenylalanine which was not used by the monkey kidney cells was utilized by the explants of chick kidney. The amino acid metabolism of freshly isolated cells from the breast muscle of the embryonic chick has lately been studied, using a completely defined medium (Lucy & Rinaldini, 1959). In these experiments, skeletal myoblasts formed fibres which were observed to contract for up to 3 days.…”

The Roles of Amino Acids in Animal Embryogenesis

“…Rothfels, 1954) resulted in blockage of somite segmentation more frequently than in other developmental defects, suggesting that somite segmentation had specific leucine requirements. Although analogues of methionine may also produce this effect(Herrmann, Konigsberg & Curry, 1955) as well as purine analogues(Waddington, Feldman & Perry, 1955) there are still some grounds for believing that leucine is of special importance to the developing somites Lucy & Rinaldini (1959),. for instance, showed that leucine is taken up preferentially from tissue culture media by developing skeletal myoblasts of the chick, and I have been able (1960b) to increase the rate of somite segmentation in chick embryos by explanting them in media containing leucine, in the absence of other extraneous amino acids.…”

Comparative Metabolic Studies on Normal and Neoplastic Rat Liver

“…T h e am ino acid re q u ire m e n ts of tissue cu ltu res h av e been stu d ied in a v a rie ty o f c u ltu re s of ex p ia n ts as well as cell lines in sy n th e tic an d se m i-sy n th etic m ed ia [10,[12][13][14][15]17]. Such stu d ies h av e p o in ted to th e d istin g u ish in g c h a ra c teristic s o f a few cu ltu res, such as th e n o n re q u ire m e n t o f g lu ta m in e b y chick h e a rt [8], th e req u irem en t of serine b y r a b b it fib ro b lasts [9], an d of a sp arag in e by W alker carcinosarcom a 256 [11].…”