[1-C-13] breath test of galactose and fructose for quantitative liver function

Background. Using a rat model of hepatectomy, we investigated whether the s everity of hepatopathy could be quantitatively measured from changes in exp iratory (CO2)-C-13 levels after intravenous administration of [1-C-13]fruct ose or [1-C-13]galactose. Materials and Methods. Under nembutal anesthesia, 100 mg/kg of [1-C-13]fruc tose or [1-C-13]galactose was administered to rats via the femoral vein, an d expiratory (CO2)-C-13 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 (CO2)-C-13 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 -C-13]fructose breath test graph reached a plateau level at about 25 min. I n the control group, the [1-C-13]galactose breath test graph reached a plat eau level, but in all groups undergoing hepatectomy a plateau level was not reached during measurement. The correlation coefficient between SP5 after [1-C-13]fructose administration and LW/BW was the highest, 0.656 (P = 0.001 7). The correlation coefficient between SP25 after [1-C-13]galactose admini stration and LW/BW was the highest, 0.923 (P < 0.0001). Conclusion. In the breath test with intravenously administered [1-C-13]fruc tose, hepatopathy could not be quantitatively evaluated accurately. However , hepatopathy could be quantitatively evaluated accurately by measuring SP2 5 in the breath test with intravenously administered [1-C-13]galactose over a short period. (C) 2001 Academic Press.