1999 Fiscal Year Final Research Report Summary
Interaction between Methionine and Branched-Chain Amino Acids in Calves
| Project/Area Number |
09660307
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied animal science
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| Research Institution | Azabu University |
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Principal Investigator |
ABE Matanobu Azabu Univ., School of Vet.Med. Professor, 獣医学部, 教授 (00120949)
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| Co-Investigator(Kenkyū-buntansha) |
IRIKI Tsunenori Azabu Univ., School of Vet.Med. Assoc. Prof, 獣医学部, 助教授 (60151693)
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| Project Period (FY) |
1997 – 1999
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| Keywords | Methionine / Toxicity / Imbalance / Antagonism / Branched-chain amino acids / Phenylalanine / Nitrogen balance / Calves |
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| Research Abstract |
Results obtained from this study are summarized as follows :
1. Adverse effects occurred when excess DL-Me was administered through the reticular groove of calves.
2. In calve aged 6 to 7 weeks, the upper limit of safety dose of DL-Me ranged from 6 g/d (0.177 g/kg BW) to 12 g/d (0.177 g/kg BW), and the lower limit of toxic dose ranged from 12 g/d (0.177 g/kg BW) to 18 g/d (0.265 g/kg BW). The intermediate dose resulted in imbalance.
3. In calves aged 12 to 13 weeks, the upper limit of safety dose of DL-Me ranged from 8 g/d (0.079 g/kg BW) to 16 g/d (0.158 g/kg BW), and the lower limit of toxic dose ranged from 24 g/d (0.237 g/kg BW) to 32 g/d (0.316 g/kg BW). The intermediate dose resulted in imbalance.
4. Toxicity was more liable to occur in young calves than in older calves, although the threshold of imbalance did not seem to be affected by age.
5. Antagonistic interaction occurred among Met, BCAA, and Phe when DL-Me was administered through the reticular groove of calves.
6. The interaction was more obvious in older calves than in young calves, and was limited to the range form 0 to 12 g DL-Met/d in 7-week-old calves.
7. The interaction was irrelative to antagonistic absorption.
8. The decrease in plasma concentrations of BCAA and Phe was related to the increase in plasma concentrations of cystathionine rather than methionine.
9. This suggested that the interaction occurred in relation to Met metabolism via the transsulfuration pathway.
10. The antagonistic interaction was suggested to have some relation to Met imbalance, even though the interaction is irrelative to Met toxicity.
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