Changes on levels of B6 vitamin and aminotransferase in the liver of diabetic animals.
We measured aminotransferase activity and vitamin B6 content in the livers of diabetic mice. Two different types of mice were used for the measurements, spontaneously non-obese diabetic (NOD) or alloxan-induced diabetic (Allo) mice, and control mice were either non-diabetic NOD or Institute of Cancer Research (ICR). The liver of diabetic mice had more aspartate aminotransferase (AST) activity than those of normal mice. The diabetic livers also had more vitamin B6 than did normal livers, and pyridoxamine (PM) levels were particularly high but pyridoxal (PL) levels were not. ICR livers showed hepatic alanine aminotransferase activities inversely correlated with blood glucose concentrations, while diabetic livers did not. The abundance of AST and B6 in the diabetic liver is consistent with the great need for gluconeogenic substrate there. This is understandable in that most aminotransferases require B6 vitamins, and especially the correlation between s-AST and PM levels was recognized in the diabetic liver. Conversely, the AST and PM levels were negatively correlated in normal mice. A metabolic shift towards gluconeogenesis apparently produces more B6 and PM while it induced holo-AST synthesis.
Nanbara
S
S
Department of Clinical Pathology, Osaka Medical College, Takatsuki, Japan.
Tanaka
K
K
Koide
H
H
Tanaka
T
T
Hayashi
T
T
D000410:Alanine Transaminase / Q000378:metabolism*; D000818:Animals; D001051:Apoenzymes / Q000378:metabolism; D001219:Aspartate Aminotransferases / Q000378:metabolism*; D003600:Cytosol / Q000201:enzymology; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D051379:Mice; D008813:Mice, Inbred ICR; D008815:Mice, Inbred Strains; D011733:Pyridoxamine / Q000378:metabolism; D011736:Pyridoxine / Q000378:metabolism*; D012016:Reference Values
D001051:Apoenzymes; D011733:Pyridoxamine; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D011736:Pyridoxine