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Transfer of Amino-Acids Through Mucous Rumen Membrane of Sheep Invitro

FEJES J, FAIXOVA Z, VARADY J, CIBULA M
Veterinarni Medicina 36, 1991, 551-559

Transfer of six amino acids through rumen epithelium of sheep has been studied on mucous and serous sides. Amino acids were classified into two groups: 1. lysinearginine-glutamic acid, 2. glycine-alanine-leucine. The transfer of amino acids in triads was measured after 60 min. incubation. To determine amino acids transfer through rumen epithelium, three concentrations of amino acids were used: 1500: 150 and 15-mu-mol per 50 ml. In the first group of amino acids, the highest transfer of arginine was found in comparison with lysine and glutamic acid in all concentrations [Fig. 1]. The lowest transfer was found in glutamic acid. It follows from this that initial concentration of amino acids in the first group had no effect on amino acids transfer as far as the transfer of amino acids was as follows in all concentrations: arginine > lysine > glutamic acid. On the other hand, the composition of amino acids and initial concentration of amino acids in the second group exhibited the marked dependence on the transport of amino acids [Fig. 2]. The transfer of amino acids at the concentration of 1500-mu-mol per 50 ml was as follows: the passage of amino acids was the highest while this was lowest in alanine and leucine, at the concentration 150-mu-mol per 50 ml the highest transfer was found in alanine, it was lower in glycine and lowest in leucine and at the concentration 15-mu-mol per 50 ml the transfer of glycine was highest, lower in leucine and lowest in alanine. By summing up the concentrations of amino acids on mucous and serous sides of rumen after 60 minute incubation, it was found out that their sum is higher in some cases at the mucous side of rumen epithelium in comparison with original concentration of amino acids before incubation. This fact indicates that amino acids were either released from rumen mucose or they were synthetized by adherent rumen bacteria which are closely connected with rumen epithelium by polysaccharide glycocalyx fibres. The results obtained confirm the fact that the transport of amino acids through rumen epithelium is dependent on composition and concentration of amino acids in the rumen contents and an important role in this process is played by rumen epithelium alone. ruminants


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