SHORT COMMUNICATIONS: 15~N enrichment of casein amino acids in the milk from goats given a single intravenous dose of L-[5~N]leucine

摘要

Branched-chain amino acids (AA) are mostly metabolized in the splanchnic area, but some are metabolized within the mammary gland and thus could contribute to the synthesis of non-essential A (Wohlt et al. 1977). The extraction rate of leucine from plasma by the mammary gland is particularly high (64/100 in the goat; Roets et al. 1983), in excess of that used for the synthesis of milk proteins (Davis & Mepham, 1976; Wohlt et al. 1977; Roets et al. 1983). Thus, although mammary leucine is mainly used for milk protein, it also provides amino nitrogen and carbon sources for the synthesis of non-essential AA.