Detection of Hepatic Ischemic Injury in Simple Storage by Electrical Impedance

Kimi Yamauchi, Hajime Hirose, Syoushi Senga, Katutomo Hayashi, Atsuyoshi Onituka, Shizuko Syoumura*

First Department of Surgery, First Department of Anatomy*, Gifu University School of Medicine

Electrical properties of the liver, especially when they are measured at various frequencies, reflect its structural and physiological changes. This study was designed to examine viability during preservation of the liver by measurement of electrical impedance. The liver was preserved by simple storage in saline. Livers were divided into three groups according to the preserving temperature: Group I, 4°C (n=6); Group II, 15°C (n=6) and Group III, 25°C (n=6). They were examined for morphorogical changes by electron microscopy during the preservation. Two hundred and forty minutes in Group I, 120 minutes in Group II, 60 minutes in Group III were the times for a mitochondrial score below 3. Adenine nucleotide (ATP) levels of the preserved liver were measured by high pressur liquid chromatography. Percent ATP decreased 18-21% of the preischemia level at the same times described above in each group. Permittivity and conductivity in measurement of electrical impedance were measured at 39 frequency points in the 20 Hz-1 MHz range with an LCR meter system. Then tan δ was calculated from the permittivity and conductivity, as a function of frequency. Percent tan δ decreased immediately after ischemic injury and changed between 0.033-0.086%/min at the time for a mitochondrial score below 3. Significant correlation between percent ATP and percent tan δ was found in all groups. These results suggest that measurement of electrical impedance could be an index of the viability of the preserved liver.

Key words
simple strage, electrical impedance, ultrastructure, adenine nucleotide, water content

Reprint requests
Kimi Yamauchi First Department of Surgery, Gifu University School of Medicine
40 Tukasa-cho, Gifu-city, 500 JAPAN

Accepted
October 9, 1996

To read the PDF file you will need Abobe Reader installed on your computer.