J.Jpn. Surg. Soc.. 81(5): 427-440, 1980
Original article
EXPERIMENTAL STUDIES ON THE ISCHEMIC TOLERANCE OF THE LIVER ―ITS PREDICTION AND ENHANCEMENT
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The First Department of Surgery, Hokkaido University School of Medicine (Director : Prof. Yoichi Kasai) Takeyasu Taira |
Methods:
A) The rat livers in situ, of ischemic periods up to 70 min., are examined for tissue adenin nucleotides. This is repeated one hour after revascularizing the liver. The rats are observed thereafter and mortality rate was obtained.
B) The isolated rat livers are perfused with perfusates which contain perfluorochemical (PFC). They are then examined for adenin nucleotides, gluconeogenesis etc., at given intervals.
Results:
1) The hepatic energy level decreased with initiation of ischemia, it was, however, restored by revascularization to the normal level when ischemic period was less than 20 min.
2) The hepatic ATP level (depicted by “R” in ratio to the normal level) showed a rapid decrease to reach its minimum value of R= 13% at 10－15 min., then increased up to R= 17% at 25 min., and kept decreasing thereafter.
3) The “R” value after revascularization showed significant correlation with the ischemic period (“T” in hour) by R=－0.596T+1.04, (P＜0.01).
4) The gradient “A”, a parameter to govern the hepatic ATP level, was obtained by plotting values of “A” calculated by R=AT for the ischemic livers, and by R=A(T + 1) for them after revascularization. It was found to significantly correlate with the mortality rate (“Y” in probit) by Y=－7.5A+7.2, (P＜0.01). Furthermore, having “T” as a factor to determine “A”, a equation was obtained; A=1.636/(T+1)－0.596.
Based on these equations, it became possible to predict survival rate of thus treated animals by having only “T” as a determining factor. Thus, it was calculated that “T” of 50 min. yielded “A” of 0.29 which corresponded to 100% survival of the animals without insult of sampling hepatectomy.
5) The PFC in concentration of 10w/v% was found to most effectively enhance energy production and gluconeogenesis among various perfusates and to prolong the tolerance of ischemic period up to 120 min. as predicted by having R=0.29T in the above calculations.
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