Effects of cysteine on amino acid concentrations and transsulfuration enzyme activities in rat liver with protein-calorie malnutrition.
The changes in amino acid concentrations and transsulfuration enzyme activities in liver were investigated after 4-week fed on 23% casein diet (control group) and 5% casein diet without (protein-calorie malnutrition, PCM group) or with (PCMC group) oral administration of cysteine, 250 mg/kg (twice daily, starting from the fourth week) using rats as an animal model. By supplementation with cysteine in PCM rats (PCMC group), cysteine level was elevated almost close to the control level, and glutathione (GSH), aspartic acid and serine levels were restored greater than the control levels. The measurement of transsulfuration enzyme activities exhibited that gamma-glutamylcysteine ligase (gamma-GCL) activity was up-regulated in rats with protein restriction (PCM group), and cysteine supplementation (PCMC group) down-regulated to the control level. One-week supplementation of cysteine (PCMC group) significantly down-regulated the cysteine sulfinate decarboxylase activity. These results indicate that the availability of sulfur amino acid(s) especially cysteine appears to play a role in determining the flux of cysteine between cysteine catabolism and GSH synthesis.
Kim
Yoon G
YG
Department of Pharmacology, College of Medicine, Dankook University, San 29, Anseo-Dong, Chonan, Chungcheongnam-Do 330-714, South Korea.
Kim
Sang K
SK
Kwon
Jong W
JW
Park
Ock J
OJ
Kim
Sang G
SG
Kim
Young C
YC
Lee
Myung G
MG
D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D002262:Carboxy-Lyases / Q000378:metabolism; D003541:Cystathionine beta-Synthase / Q000378:metabolism; D003545:Cysteine / Q000494:pharmacology*; D050558:Cysteine Dioxygenase; D003600:Cytosol / Q000187:drug effects / Q000201:enzymology; D004032:Diet; D049308:Dioxygenases; D004435:Eating / Q000187:drug effects; D005721:Glutamate-Cysteine Ligase / Q000378:metabolism; D008099:Liver / Q000201:enzymology*; D008297:Male; D009929:Organ Size / Q000187:drug effects; D010105:Oxygenases / Q000378:metabolism; D011502:Protein-Energy Malnutrition / Q000201:enzymology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects; D013455:Sulfur / Q000378:metabolism*; D015430:Weight Gain / Q000187:drug effects
D000596:Amino Acids; D013455:Sulfur; D010105:Oxygenases; D049308:Dioxygenases; D050558:Cysteine Dioxygenase; D002262:Carboxy-Lyases; C019972:sulfoalanine decarboxylase; D003541:Cystathionine beta-Synthase; D005721:Glutamate-Cysteine Ligase; D003545:Cysteine