Amino acids and lactate efflux from in vitro incubated soleus muscles of suckling rats.

The net in vitro release of lactate, pyruvate, alanine, glutamate, glutamine and total amino acids from soleus muscles of suckling rats was studied. In all cases, the net output of metabolites was considerably higher in young animals than in 30 day old controls. Glutamine efflux of 1 day old pups was very low, probably due to lack of effectivity of the glutamine synthesizing system. The considerable output of amino acids in the younger animals was partly due to depletion of internal amino acid pools.