PURPOSE: We have demonstrated impaired mitochondrial viability and function during pulmonary ischemia reperfusion injury(IR). Resveratrol(Res) has demonstrated to ameliorate the IR of various organs. This study analyzes the impact of Res-preconditioning on pulmonary IR-induced mitochondrial dysfunction and tissue damage.
METHODS: Rats (n=6,each) were subjected to controls, Shams without(Sham) or with preconditioning by 5µg Res i.v.(Res-Sham) and two study group conditions receiving IR without(IR) or with Res-preconditioning(Res-IR). IR was induced by 30min of left pulmonary clamping, followed by 60min reperfusion-time. Respiratory chain complex activities(I-V,II-V,III-V) were analyzed in isolated mitochondria (polarography). Mitochondrial membrane potential (ΔΨm) was determined in JC1-stained mitochondria after energizing and 0 to 3 min after uncoupling (FACS). Viability testing was performed using Ca2+-induced swelling (Photometry). Cytochrome C (CytC) liberation was detected (ELISA). Tissue was analyzed for matrix-metalloproteinase-9 (MMP-9) activity (Zymography), myeloperoxidase (MPO) activity and GSH content and oxidation (Colorimetry). Statistical analysis was performed in terms of ANOVA.
RESULTS: Comparing to controls IR impaired mitochondrial viability(P<.001 ). Viability was preserved by RES(P<.001 ). Swelling was inhibited in Res-Sham. In comparison to controls, IR derogated respiratory chain-function(I-V:P<.01;II-V:P<.01;III-V:P<.01) but complex-activities were preserved in Res-IR (I-V:P< 0.05;II-V:P<.05;III-V:P<.05). ΔΨm demonstrated hyper-polarization combined with increased ΔΨm-susceptibility against uncoupling in IR, Res-Sham and Res-IR(all P>.05). In IR MMP-9(P<.001), CytC-liberation(P<.001) and MPO-activities(P<.001) were increased but Res-preconditioning protected from MMP-9-(P<.01), MPO-activation(P<.05) and CytC-liberation(P>.05). In IR, observed decay in total GSH(P<.001) was insignificantly ameliorated by Res-IR(P>.05)
CONCLUSIONS: During IR, Res protects from mitochondria-induced tissue injury, oxidative stress, tissue degradation and inflammation. Disorder of ΔΨm appeared to be adverted by Res.
CLINICAL IMPLICATIONS: Res appears to be a promising drug to prevent pulmonary grafts from IR.
DISCLOSURE: The following authors have nothing to disclose: Sebastian-Patrick Sommer, Stefanie Sommer, Bhanu Sinha, Daniel Schäfer, Christoph Otto, Ivan Aleksic, Anne Sophie Mehdorn, Rainer Leyh
This study evaluates the clinical impact of the chemical compund Resveratrol in the setting of the pulmonary ischemia reperfusion injury.