Measurement of po2 in liver using epr oximetry.
Jiang, Jinjie, Toshiaki Nakashima, Ke Jian Liu, Fuminori Goda, Toshi
Shima, Harold M. Swartz.
Department of Radiology, Dartmouth Medical School, Hanover, NH
03755
APStracts 2:0435A, 1995.
Using India ink and lithium phthalocyanine (LiPc) as EPR oximetry
probes, the oxygen tension (pO2) of the liver was investigated in
mice. Since India ink was taken up by the Kupffer cells of the liver,
the EPR signal of the India ink reflected the average pO2 in
phagocytic vesicles of these cells. The mean value of pO2 in the
Kupffer cells measured by India ink was 15.3 +/- 4.4 mm Hg in
unanesthetized animals. LiPc was administered as a macroscopic
crystal and therefore reflected the pO2 of the overall liver. The pO2
measured by LiPc was 23.4 +/- 4.4 mm Hg which is consistent with the
median value of 23.5 mm Hg reported previously with the use of an
oxygen electrode. Anesthesia (intraperitoneal injection of 60 mg/kg
sodium pentobarbital) decreased the average pO2 in both Kupffer cells
and the overall liver. The effects of perturbing the blood flow were
studied by reversible blockage of the portal vein and hepatic artery
in anesthetized mice; the pO2 both in Kupffer cells (measured with
India ink) and in overall liver (measured with LiPc) decreased with
obstruction of the blood flow and returned toward normal with
reperfusion. These results indicate that the pO2 in different
locations in the liver can be significantly different under both
normal conditions and after perturbation by either anesthesia or
ischemia. These results also demonstrate that EPR oximetry can
provide sensitive measurements of pO2 in the liver in vivo under
various conditions.
Received 8 May 1995; accepted in final form 19 September 1995.
APS Manuscript Number A500-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95