TY - JOUR
T1 - Leucine accelerates blood ethanol oxidation by enhancing the activity of ethanol metabolic enzymes in the livers of SHRSP rats
AU - Murakami, Hitoshi
AU - Ito, Michiko
AU - Furukawa, Yuji
AU - Komai, Michio
PY - 2012/12/1
Y1 - 2012/12/1
N2 - Chronic ethanol consumption induces liver diseases, such as alcoholic hepatitis and cirrhosis. The enhancement of alcohol oxidation is important in the prevention of these liver diseases. Chronic supplementation with branched chain amino acids (BCAAs) prevents liver cirrhosis. Therefore, BCAAs may be associated with enhanced ethanol oxidation. To evaluate this hypothesis, we investigated the effect of the administration of individual BCAAs on ethanol oxidation and changes in alcohol-metabolizing enzyme activities following acute alcohol intake in rats. Blood ethanol concentrations and the activities of alcohol-metabolizing enzymes, such as alcohol dehydrogenase (ADH) and low and high Km aldehyde dehydrogenase (ALDH), were measured in the liver following acute ethanol administration in rats; the ethanol was administered 30 min after the treatment with amino acids [such as leucine (Leu), isoleucine (Ile), valine (Val) or alanine (Ala)]. Leu significantly decreased the blood ethanol concentration 1 h after ethanol administration compared to the water-treated control (C) [C 0.46 ± 0.09, Leu 0.18 ± 0.04, Ile 0.27 ± 0.09, Val 0.46 ± 0.1, Ala 0.43 ± 0.06, mean ± SEM (g/l), P\0.05]. In addition, leucine significantly stimulated ADH activity 30 min after ethanol intake [C 0.042 ± 0.014, Leu 0.090 ± 0.016, Ile 0.042 ± 0.008, Val 0.022 ± 0.010, Ala 0.070 ± 0.016, mean ± SEM (unit/mg protein), P\0.05] and low Km ALDH activity 15 min after ethanol intake [C 0.51 ± 0.63, Leu 3.72 ± 0.66, Ile 1.26 ± 0.89, Val: ND, Ala 1.86 ± 1.57, mean ± SEM (unit/mg protein), P\0.05]. However, leucine and its metabolite a-keto-isocaproic acid did not enhance ethanol clearance in isolated rat hepatocytes. These results indicate that leucine accelerates ethanol oxidation by indirectly enhancing ADH and low Km ALDH activities in the liver.
AB - Chronic ethanol consumption induces liver diseases, such as alcoholic hepatitis and cirrhosis. The enhancement of alcohol oxidation is important in the prevention of these liver diseases. Chronic supplementation with branched chain amino acids (BCAAs) prevents liver cirrhosis. Therefore, BCAAs may be associated with enhanced ethanol oxidation. To evaluate this hypothesis, we investigated the effect of the administration of individual BCAAs on ethanol oxidation and changes in alcohol-metabolizing enzyme activities following acute alcohol intake in rats. Blood ethanol concentrations and the activities of alcohol-metabolizing enzymes, such as alcohol dehydrogenase (ADH) and low and high Km aldehyde dehydrogenase (ALDH), were measured in the liver following acute ethanol administration in rats; the ethanol was administered 30 min after the treatment with amino acids [such as leucine (Leu), isoleucine (Ile), valine (Val) or alanine (Ala)]. Leu significantly decreased the blood ethanol concentration 1 h after ethanol administration compared to the water-treated control (C) [C 0.46 ± 0.09, Leu 0.18 ± 0.04, Ile 0.27 ± 0.09, Val 0.46 ± 0.1, Ala 0.43 ± 0.06, mean ± SEM (g/l), P\0.05]. In addition, leucine significantly stimulated ADH activity 30 min after ethanol intake [C 0.042 ± 0.014, Leu 0.090 ± 0.016, Ile 0.042 ± 0.008, Val 0.022 ± 0.010, Ala 0.070 ± 0.016, mean ± SEM (unit/mg protein), P\0.05] and low Km ALDH activity 15 min after ethanol intake [C 0.51 ± 0.63, Leu 3.72 ± 0.66, Ile 1.26 ± 0.89, Val: ND, Ala 1.86 ± 1.57, mean ± SEM (unit/mg protein), P\0.05]. However, leucine and its metabolite a-keto-isocaproic acid did not enhance ethanol clearance in isolated rat hepatocytes. These results indicate that leucine accelerates ethanol oxidation by indirectly enhancing ADH and low Km ALDH activities in the liver.
KW - Alcohol metabolic enzymes
KW - Ethanol oxidation
KW - Leucine
UR - http://www.scopus.com/inward/record.url?scp=84872685404&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84872685404&partnerID=8YFLogxK
U2 - 10.1007/s00726-012-1406-8
DO - 10.1007/s00726-012-1406-8
M3 - Article
C2 - 23053019
AN - SCOPUS:84872685404
VL - 43
SP - 2545
EP - 2551
JO - Amino Acids
JF - Amino Acids
SN - 0939-4451
IS - 6
ER -