Abstract
The developmental changes of glutamate dehydrogenase activity in the fetal and neonatal rat liver were investigated, as well as the effects of branched-chain amino acids on this enzyme. Hepatic glutamate dehydrogenase activity showed a marked increase at the end of the fetal period and peaked on the 5th day of neonate at approximately 3 times higher than the adult level. Glutamate dehydrogenase was activated by leucine, isoleucine, and valine in this order when they were added to isolated intact liver mitochondria in vitro. The enhancement of enzyme activity was more marked in fetal rats than in adults. In contrast, when branched-chain amino acids were added after disrupting the mitochondrial membrane by sonication, only leucine slightly activated glutamate dehydrogenase, while isoleucine and valine slightly inhibited its activity. Our findings suggest that glutamate may be actively synthesized in the developing rat liver mitochondria and then trans-aminated to other nonessential amino acids for protein synthesis, and that increased intramitochondrial branched-chain amino acid concentrations may enhance glutamate dehydrogenase activity. This anabolic metabolism will contribute to the fetal growth and development.
| Original language | English |
|---|---|
| Pages (from-to) | 83-88 |
| Number of pages | 6 |
| Journal | Neonatology |
| Volume | 62 |
| Issue number | 2-3 |
| DOIs | |
| Publication status | Published - 1992 |
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Keywords
- Branched-chain amino acids
- Developing rat liver
- Glutamate dehydrogenase
- Mitochondria
ASJC Scopus subject areas
- Developmental Biology
- Pediatrics, Perinatology, and Child Health
Cite this
Developmental changes of glutamate dehydrogenase activity in rat liver mitochondria and its enhancement by branched-chain amino acids. / Eguchi, Katsuto; Yonezawa, Masaru; Mitsui, Yukiteru; Hiramatsu, Yuji.
In: Neonatology, Vol. 62, No. 2-3, 1992, p. 83-88.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Developmental changes of glutamate dehydrogenase activity in rat liver mitochondria and its enhancement by branched-chain amino acids
AU - Eguchi, Katsuto
AU - Yonezawa, Masaru
AU - Mitsui, Yukiteru
AU - Hiramatsu, Yuji
PY - 1992
Y1 - 1992
N2 - The developmental changes of glutamate dehydrogenase activity in the fetal and neonatal rat liver were investigated, as well as the effects of branched-chain amino acids on this enzyme. Hepatic glutamate dehydrogenase activity showed a marked increase at the end of the fetal period and peaked on the 5th day of neonate at approximately 3 times higher than the adult level. Glutamate dehydrogenase was activated by leucine, isoleucine, and valine in this order when they were added to isolated intact liver mitochondria in vitro. The enhancement of enzyme activity was more marked in fetal rats than in adults. In contrast, when branched-chain amino acids were added after disrupting the mitochondrial membrane by sonication, only leucine slightly activated glutamate dehydrogenase, while isoleucine and valine slightly inhibited its activity. Our findings suggest that glutamate may be actively synthesized in the developing rat liver mitochondria and then trans-aminated to other nonessential amino acids for protein synthesis, and that increased intramitochondrial branched-chain amino acid concentrations may enhance glutamate dehydrogenase activity. This anabolic metabolism will contribute to the fetal growth and development.
AB - The developmental changes of glutamate dehydrogenase activity in the fetal and neonatal rat liver were investigated, as well as the effects of branched-chain amino acids on this enzyme. Hepatic glutamate dehydrogenase activity showed a marked increase at the end of the fetal period and peaked on the 5th day of neonate at approximately 3 times higher than the adult level. Glutamate dehydrogenase was activated by leucine, isoleucine, and valine in this order when they were added to isolated intact liver mitochondria in vitro. The enhancement of enzyme activity was more marked in fetal rats than in adults. In contrast, when branched-chain amino acids were added after disrupting the mitochondrial membrane by sonication, only leucine slightly activated glutamate dehydrogenase, while isoleucine and valine slightly inhibited its activity. Our findings suggest that glutamate may be actively synthesized in the developing rat liver mitochondria and then trans-aminated to other nonessential amino acids for protein synthesis, and that increased intramitochondrial branched-chain amino acid concentrations may enhance glutamate dehydrogenase activity. This anabolic metabolism will contribute to the fetal growth and development.
KW - Branched-chain amino acids
KW - Developing rat liver
KW - Glutamate dehydrogenase
KW - Mitochondria
UR - http://www.scopus.com/inward/record.url?scp=0026760971&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026760971&partnerID=8YFLogxK
U2 - 10.1159/000243858
DO - 10.1159/000243858
M3 - Article
C2 - 1420617
AN - SCOPUS:0026760971
VL - 62
SP - 83
EP - 88
JO - Neonatology
JF - Neonatology
SN - 1661-7800
IS - 2-3
ER -