Acetate as a precursor of amino acids of casein in the intact dairy cow

On the Amino Acids Essential for the Tissues of the Sheep

“…The results showed that only the following amino acids became labelled: glutamic acid, aspartic acid, proline, alanine, arginine, and serine. By analogy with earlier work on cows by Black et al (1957) it was concluded that these amino acids are also non· essential for the tissues of the sheep.…”

“…The results showed that only the following amino acids became labelled: glutamic acid, aspartic acid, proline, alanine, arginine, and serine. By analogy with earlier work on cows by Black et al (1957) it was concluded that these amino acids are also non· essential for the tissues of the sheep.The casein isolated from the milk produced during the first few hours had a much higher specific activity than the maximum observed in the wool. However, the results were consistent with the hypothesis that neither the wool keratin nor the casein were formed from the plasma proteins.…”

“…The specific activities of the individual amino acids from the second casein sample are shown in Table 2, together with the corresponding results obtained by Black et al (1957) for the amino acids from casein produced by cows during the first 3 hr after an injection of sodium [1-14C]acetate. For this comparison both sets of results are expressed as fLc per g-atom of carbon divided by the number of microcuries injected per kg of body weight.…”

“…For this comparison both sets of results are expressed as fLc per g-atom of carbon divided by the number of microcuries injected per kg of body weight. The amino acids whose counting rates were above background (8 counts/min) when counted at infinite thickness on 1·cm 2 polythene disks are compared in the last two columns with the corresponding mean results published by Black et al (1957) * Essential for maintenance of nitrogen equilibrium in normal adult man.…”

“…However, some evidence has now been obtained by applying the indirect method outlined above. In this paper a comparison is made between some results obtained in the sheep and those published for the cow after an injection of sodium [P4C]acetate (Black et al 1957).…”