Rates of gluconeogenesis in perfused liver of alloxan-diabetic fed rats.
The maximal capacity of the liver to produce glucose was examined using a technique, which permited to investigate gluconeogenesis in diabetic fed rats. Diabetes was obtained with an iv injection of alloxan (40 mg/kg). Livers from diabetic fed rats were perfused in situ and gluconeogenesis from different glucose precursors were measured one week after alloxan injection. Hepatic gluconeogenesis from L-alanine (5 mM) was absent. However, increased urea, pyruvate and L-lactate production was observed during L-alanine infusion. Differently of L-alanine, alloxan-diabetic fed rats showed increased hepatic glucose production from pyruvate (5 mM), L-lactate (2 mM) and D-frutose (5 mM). Additionally, increased L-lactate production from pyruvate and pyruvate production from L-lactate were observed. However, pyruvate production from L-lactate was lower in the diabetic group when compared with control group. Moreover similar tendency were observed for L-alanine and D-frutose. Taken together our results demonstrate influence of the cytosolic redox potential (NADH/NAD+ ratio) in the metabolic fate L-alanine. Additionally, in contrast to L-alanine, diabetic rats not only showed increased rate of glucose production from L-glutamine (5 mM) but also higher values than control rats.
Akimoto
L S
LS
Department of Clinical Analysis, State University of Maringá, PR, Brazil.
Pedrinho
S R
SR
Lopes
G
G
Bazotte
R B
RB
D000496:Alloxan; D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000378:metabolism*; D005632:Fructose / Q000378:metabolism; D005943:Gluconeogenesis / Q000187:drug effects*; D005947:Glucose / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D019344:Lactic Acid / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D008297:Male; D009243:NAD / Q000378:metabolism; D010477:Perfusion; D019289:Pyruvic Acid / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014527:Uric Acid / Q000378:metabolism
D005973:Glutamine; D009243:NAD; D014527:Uric Acid; D005632:Fructose; D019344:Lactic Acid; D000496:Alloxan; D019289:Pyruvic Acid; D005947:Glucose