technetium-tc-99m-mebrofenin and Reperfusion-Injury

Liver ischaemia may lead to parenchymal damage depending on the duration of the ischaemia. Dimethylsulphoxide (DMSO), a well-known radical oxygen scavenger, is a protective agent against ischaemia/reperfusion injury. In this study we aimed to investigate the role of hepatobiliary scintigraphy (HBSc) in detecting the protective effect of DMSO. Eighteen rabbits, in three groups of six, were injected with 37 MBq technetium-99m-mebrofenin via the ear veins. Dynamic scintigrams were taken for 60 min (1 frame/min). In group A, HBSc was performed without any surgery. In groups B and C the Pringle manoeuvre (PM) was applied for 30 min, and tissue specimens for electron microscopy were taken from the liver parenchyma 5 min after the end of the PM. In addition, in group C 1 g/kg DMSO was injected into each rabbit 5 min before application of the PM. HBSc was then performed in groups B and C. From the dynamic images time-activity curves (TACs) were obtained for each group, and the time of peak uptake (TPU) and time for half of the activity to clear from the liver (T1/2) were calculated. The TPU and T1/2 of group B were significantly longer than those of groups A and C (P<0.0005 and P<0.005 for TPU, and P<0.0005 and P<0.02 for T1/2, respectively). The TPU and T1/2 of group C were significantly longer than those of group A (P < 0.005 and P < 0.02, respectively). While the electron microscopic images in group C showed reversible changes, those in group B showed both irreversible and reversible changes. The electron microscopic findings of groups B and C confirmed the scintigraphic findings. In conclusion, HBSc might be used as a practical quantitative method for detecting the protective effects of DMSO. However, its clinical value should be evaluated by further studies with human subjects.

Topics: Aniline Compounds; Animals; Biliary Tract; Cell Death; Dimethyl Sulfoxide; Glycine; Imino Acids; Liver; Liver Circulation; Microscopy, Electron; Organotechnetium Compounds; Rabbits; Radionuclide Imaging; Radiopharmaceuticals; Reperfusion Injury

The kinetics of 99mTc-Trimethyl-Br-IDA blood clearance was analysed in the rat 24 h after warm ischaemia and reperfusion of the liver. There were changes in the elimination of 99mTc-Trimethyl-Br-IDA depending on the length of the ischaemic period and the dose given. Statistically significant differences were found between the various periods of ischaemia when higher doses of the radionuclide were utilised. At lower doses, the clearance was not capable to discriminate between control rats and rats submitted to 45 min of ischaemia, but it did discriminate more severe degrees of ischaemic liver injury. Instead, galactose elimination capacity discriminated between ischaemic and control rats, but not between 45 and 90 min or between 90 and 120 min of ischaemia. Alanine aminotransferase was able to discriminate between control and ischaemic rats and between 45 and 90 min of ischaemia, but not between 90 and 120 min of ischaemia. The response of 99mTc-Trimethyl-Br-IDA clearance under extreme conditions of ischaemia and reperfusion is consistent and opens a possible window for the application of this test in the quantification of liver function in severely damaged livers and in decision making and prognosis in liver disease.

Topics: Alanine Transaminase; Aniline Compounds; Animals; Galactosemias; Glycine; Imino Acids; Ischemia; Liver; Liver Circulation; Male; Organotechnetium Compounds; Radiopharmaceuticals; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Severity of Illness Index; Time Factors