1-13C]Galactose Breath Test for Quantitative Measurement of Liver Function in a Short Period

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]galactose. Materials and Methods: Under nembutal anesthesia, 100 mg/kg [1-¹³C]galactose was administered to rats via the femoral vein, and expiratory ¹³CO₂ levels were measured for 60 min. Then, 30, 70 or 90% hepatectomy was performed. In the control group, simple laparotomy was performed. Breath test was conducted 20 min after laparotomy. We examined the correlation of total ¹³CO₂ output (S) or single point ¹³CO₂ level (SP) every 5 min until 30 min, and at 45 and 60 min with liver weight/body weight (LW/BW) (%). Results: In the control group, the 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 S³⁰ after [1-¹³C]galactose administration and LW/BW was 0.889 (p < 0.0001). The correlation coefficient between SP²⁵ after [1-¹³C]galactose administration and LW/BW was highest, 0.923 (p < 0.0001). Conclusion: In the breath test with intravenously administered [1-¹³C]galactose, hepatopathy could be evaluated by measuring S³⁰ and hepatopathy could be more accurately quantitatively evaluated by measuring SP²⁵ over a short period.