Ornithine breath test as a method to evaluate functional liver volume.
BACKGROUND
The purpose of this study was to investigate whether the functional liver volume can be measured from changes in expiratory 13CO2 levels after intravenous administration of L-[1, 2-13C] ornithine, using a rat model of hepatectomy.


METHODS
Under pentobarbital anesthesia, 30%, 70%, or 90% hepatectomy was performed. In the control group, simple laparotomy was performed. Then, 20 mg/kg L-[1, 2-13C] ornithine was administered to rats via the femoral vein. A breath test was conducted 20 min after laparotomy. We examined the correlation of the sum of 13CO2 output (S) or a single point of 13CO2 level (SP) with liver weight/body weight (LW/BW) (%) every 15 min.


RESULTS
In all of the groups, the ornithine breath test (OBT) graph reached a plateau level at about 6 min. The correlation coefficient between S15 and LW/BW was highest 0.952 (P <0.0001). The correlation coefficient between SP14 and LW/BW was highest, 0.944 (P <0.0001). The severity of hepatic injury could be evaluated, with significant differences in S5-15 and SP5-15 in all comparisons between groups.


CONCLUSIONS
In the breath test with intravenously administered L-[1, 2-13C] ornithine, functional liver volume could be evaluated accurately in a short period.
Aoki
Masaru
M
Department of Surgery, Division 3, Nihon University School of Medicine, Tokyo, Japan.
Ishii
Yukimoto
Y
Asai
Satoshi
S
Ishikawa
Koichi
K
Takayama
Tadatoshi
T
D000818:Animals; D001944:Breath Tests; D006498:Hepatectomy; D008099:Liver / Q000502:physiology*; D008111:Liver Function Tests; D008115:Liver Regeneration / Q000502:physiology*; D008297:Male; D023421:Models, Animal; D009929:Organ Size / Q000502:physiology; D009952:Ornithine / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar
D009952:Ornithine