Effects of ethanol and diabetes on galactose oxidative metabolism and elimination in rats.
Blood galactose clearance after an intravenous galactose load has been widely used for years as an index of liver function. We developed a noninvasive [13C]galactose breath test, which explores galactose oxidative metabolism; this test is well correlated with liver fibrosis in patients with chronic viral hepatitis. The goal of this study was to evaluate the influence of nonhepatic factors such as diabetes and ethanol on whole-body galactose clearance (measured as the serum galactose elimination capacity test) and oxidative metabolism (measured as the [13C]galactose-induced breath 13CO2 production) in rats. Acute ethanol administration induced a significant decrease of galactose clearance and 13CO2 production. There was a significant correlation between the amount of ethanol given and the inhibition of galactose metabolism (R2 = 0.72, p < 0.0001). In streptozotocin-induced diabetic rats, the [13C]galactose-induced breath 13CO2 production was significantly reduced (p < 0.0001) and normalized by insulin treatment. However, diabetes did not decrease whole-body galactose clearance, indicating an isotopic dilution of [13C]glucose produced from [13C]galactose metabolism into the enlarged glucose pool. These results must be taken into account when using the [13C]galactose breath test as a quantitative liver function test.
Mion
F
F
Laboratoire de physiologie Lyon-Nord, Unité mixte de recherche 5578, Centre national de la recherche scientifique, Fédération des spécialités digestives, Hôpital E. Herriot, France. francois.mion@chu-lyon.fr
Géloën
A
A
Minaire
Y
Y
D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D000431:Ethanol / Q000494:pharmacology*; D005690:Galactose / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology; D008297:Male; D010084:Oxidation-Reduction; D051381:Rats; D017207:Rats, Sprague-Dawley; D013311:Streptozocin
D007328:Insulin; D002245:Carbon Dioxide; D000431:Ethanol; D013311:Streptozocin; D005690:Galactose