1-13C] Breath Test of Galactose and Fructose for Quantitative Liver Function

Abstract

Background. Using a rat model of hepatectomy, we investigated whether the severity of hepatopathy could be quantitatively measured from changes in expiratory 13CO2 levels after intravenous administration of [1-13C]fructose or [1-13C]galactose.Materials and Methods. Under nembutal anesthesia, 100 mg/kg of [1-13C]fructose or [1-13C]galactose was administered to rats via the femoral vein, and expiratory 13CO2 levels were measured for 120 min. Then, 30, 70, or 90% hepatectomy was performed. In the control group, simple laparotomy was performed. A breath test was conducted 20 min after laparotomy. We examined the correlation of a single point 13CO2 level (SP) every 5 min until 30 min, and at 45 and 60 min with liver wt/body wt (LW/BW) (%).Results. In the control group and all groups undergoing hepatectomy, the [1-13C]fructose breath test graph reached a plateau level at about 25 min. In the control group, the [1-13C]galactose breath test graph reached a plateau level, but in all groups undergoing hepatectomy a plateau level was not reached during measurement. The correlation coefficient between SP5 after [1-13C]fructose administration and LW/BW was the highest, 0.656 (P = 0.0017). The correlation coefficient between SP25 after [1-13C]galactose administration and LW/BW was the highest, 0.923 (P < 0.0001).Conclusion. In the breath test with intravenously administered [1-13C]fructose, hepatopathy could not be quantitatively evaluated accurately. However, hepatopathy could be quantitatively evaluated accurately by measuring SP25 in the breath test with intravenously administered [1-13C]galactose over a short period.