Calpain is a mediator of preservation-reperfusion injury in rat liver transplantation - PubMed (original) (raw)
Calpain is a mediator of preservation-reperfusion injury in rat liver transplantation
V Kohli et al. Proc Natl Acad Sci U S A. 1997.
Abstract
Proteases as well as alterations in intracellular calcium have important roles in hepatic preservation-reperfusion injury, and increased calpain activity recently has been demonstrated in liver allografts. Experiments were designed to evaluate (i) hepatic cytosolic calpain activity during different periods of cold ischemia (CI), rewarming, or reperfusion, and (ii) effects of inhibition of calpain on liver graft function using the isolated perfused rat liver and arterialized orthotopic liver transplantation models. Calpain activity was assayed using the fluorogenic substrate Suc-Leu-Leu-Val-Tyr-7-amino-4-methyl coumarin (AMC) and expressed as mean +/- SD pmol AMC released/min per mg of cytosolic protein. Calpain activity rose significantly after 24 hr of CI in University of Wisconsin solution and further increased with longer preservation. Activity also increased within 30 min of rewarming, peaking at 120 min. Increased durations of CI preceding rewarming resulted in significantly higher activity (P < 0.01). Calpain activity increased rapidly upon reperfusion and was significantly enhanced by previous CI (P < 0.01). Calpain inhibition with Cbz-Val-Phe methyl ester significantly decreased aspartate aminotransferase released in the isolated perfused rat liver perfusate (P < 0.05). Duration of survival after orthotopic liver transplantation using livers cold-preserved for 40 hr was also significantly increased (P < 0.05) with calpain inhibitor. In conclusion, calpain proteases are activated during each phase of transplantation and are likely to play an important role in the mechanisms of preservation-reperfusion injury.
Figures
Figure 1
Calpain activity in liver tissue increased significantly with the duration of CI. The most significant increase occurred after 24 hr of cold preservation. n = 5; mean ± SD, P < 0.001, ANOVA.
Figure 2
Calpain activity in liver flushed with cold UW and immediately rewarmed at 25°C significantly increased with the duration of rewarming. The most significant increase in calpain activity occurred after 60 min of rewarming. n = 5; P < 0.001, ANOVA.
Figure 3
After CI for 0, 12, 24, 36, or 48 hr, livers were rewarmed at 25°C. Livers preserved for 24 and 36 hr showed significantly higher calpain activity at each rewarming time as compared with livers preserved for 0 or 12 hr. n = 5 for each CI time; P < 0.01, ANOVA.
Figure 4
Calpain activity was assessed in livers perfused in an IPRL after different periods of CI. Significant increase in calpain activity was noted after 30 min of reperfusion in each CI group. Significant increase in calpain activity was noted after reperfusion. At each duration of reperfusion calpain activity was significantly higher in livers preserved for 24 and 36 hr compared with unpreserved or 12-hr preserved livers. n = 3 for each CI time; P < 0.01, ANOVA.
Figure 5
AST released in the perfusate of IPRL after inhibition of calpain and 24-hr CI. AST concentrations in the IPRL perfusate were significantly lower in animals pretreated with the calpain inhibitor Cbz-Val-Phe methyl ester. n = 7 each; mean ± SEM, ∗, P < 0.05, t test.
Figure 6
Effect of calpain inhibition on duration of early survival of rats after OLT under nonsurvival conditions. After OLT with livers from animals pretreated with the inhibitor and cold-preserved for 40 hr in UW, significantly longer survival was seen compared with the controls. n = 5 each; mean ± SEM, P < 0.05, t test.
References
- Clavien P A, Harvey P R C, Strasberg S M. Transplantation. 1992;53:957–978. - PubMed
- Takei Y, Marzi I, Kauffman F C, Currin R T, Lemasters J J, Thurman R G. Transplantation. 1990;50:14–20. - PubMed
- Clavien P A, Sanabria J S, Upadhaya A, Cywes R, Harvey P R C, Strasberg S M. Transplantation. 1993;56:44–53. - PubMed
- Nichols J C, Bronk S F, Mellgren R L, Gores G J. Gastroenterology. 1994;106:168–176. - PubMed
- Ferguson D M, Gores G J, Bronk S F, Krom R A F. Transplantation. 1993;55:627–633. - PubMed
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