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Updated: Jun 12, 2025
Improved Rodent Model of Myocardial Ischemia and Reperfusion Injury
Published on: March 7, 2022
Activation of the AMPK-mTOR Pathway by Astaxanthin Against Cold Ischemia-Reperfusion in Rat Liver
Shujun Lu1, Yajing Zhang2, Wenli Yu1
1Department of Anesthesiology, Tianjin First Central Hospital.
Abstract:
To investigate the protective effect and mechanism of astaxanthin on myocardial injury through activation of AMPK-mTOR pathway. In this study, 32 SPF adult male Wistar rats aged 8 to 10 weeks, weighing 250-300 g were divided into 4 groups (n = 8): sham surgery group (S group), autologous orthotopic liver transplantation group (T group), astaxanthin pretreatment surgery group (Group A) and compound C + astaxanthin pretreatment surgery group (Group C). Group A was given astaxanthin 500 mg/kg, group C received compound C 50 mg/kg + astaxanthin 500 mg/kg once a day for 2 weeks, group S and T received same volume of 0.9% saline. 8 h after portal vein opening, blood samples were collected to determine serum concentrations of TNF-α, IL-6 and HMGB 1 and myocardial injury markers. Myocardial tissue was collected to determine the MDA content, SOD activity and activation of AMPK-mTOR pathway. Compared with the S group, higher serum concentrations of TNF-α, IL-6, HMGB 1, CK-MB, cTnI, and H-FABP in groups T, A, and C, increased MDA content and decreased SOD activity, higher expression of activated Caspase-3 was observed; Compared with the T group, in group A, the serum concentrations of TNF-α, IL-6, and HMGB 1, CB-MB, cTnI, and H-FABP were significantly decreased, with decreased MDA content, increased SOD activity, the reduced expression of activated Caspase-3, elevated P-AMPK/AMPK, and decreased P-mTOR/mTOR. In Conclusion, Astaxanthin protects against liver ischemia-induced myocardial injury in rats mediating by the activation of the AMPK-mTOR pathway.
Insights
Astaxanthin protects against myocardial injury following liver ischemia in rats. It achieves this by activating the AMPK-mTOR pathway, reducing inflammation and cell damage.
Area of Science:
- Cardiology
- Pharmacology
- Biochemistry
Background:
- Myocardial injury is a significant complication following liver ischemia.
- The AMPK-mTOR pathway plays a crucial role in cellular energy homeostasis and survival.
- Astaxanthin is a potent antioxidant with potential cardioprotective properties.
Purpose of the Study:
- To investigate the protective effects of astaxanthin on myocardial injury induced by liver ischemia in a rat model.
- To elucidate the underlying mechanism involving the activation of the AMPK-mTOR pathway.
Main Methods:
- 32 male Wistar rats were divided into sham surgery, liver transplantation, astaxanthin pretreatment, and compound C + astaxanthin groups.
- Biochemical markers of inflammation (TNF-α, IL-6, HMGB1), myocardial injury (CK-MB, cTnI, H-FABP), and oxidative stress (MDA, SOD) were measured.
- Activation of the AMPK-mTOR pathway and Caspase-3 expression in myocardial tissue were assessed.
Main Results:
- Liver ischemia significantly increased inflammatory markers, myocardial injury indicators, MDA, and activated Caspase-3, while decreasing SOD activity.
- Astaxanthin pretreatment significantly attenuated these detrimental effects.
- Astaxanthin administration led to elevated P-AMPK/AMPK and decreased P-mTOR/mTOR ratios, indicating AMPK-mTOR pathway activation.
Conclusions:
- Astaxanthin demonstrates significant protective effects against liver ischemia-induced myocardial injury in rats.
- The cardioprotective mechanism of astaxanthin involves the activation of the AMPK-mTOR pathway.
- Astaxanthin may be a promising therapeutic agent for preventing myocardial damage in conditions involving liver ischemia.
