Magnesium sulfate mitigates lung injury induced by bilateral lower limb ischemia-reperfusion in rats.

Abstract

BACKGROUND:

Lower limb ischemia-reperfusion (I/R) elicits oxidative stress and causes inflammation in lung tissues that may lead to lung injury. Magnesium sulfate (MgSO(4)) possesses potent anti-oxidation and anti-inflammation capacity. We sought to elucidate whether MgSO(4) could mitigate I/R-induced lung injury. As MgSO(4) is an L-type calcium channel inhibitor, the role of the L-type calcium channels was elucidated.

MATERIALS AND METHODS:

Adult male rats were allocated to receive I/R, I/R plus MgSO(4) (10, 50, or 100 mg/kg), or I/R plus MgSO(4) (100 mg/kg) plus the L-type calcium channels activator BAY-K8644 (20 μg/kg) (n = 12 in each group). Control groups were run simultaneously. I/R was induced by applying rubber band tourniquets high around each thigh for 3 h followed by reperfusion for 3 h. After euthanization, degrees of lung injury, oxidative stress, and inflammation were determined.

RESULTS:

Arterial blood gas and histologic assays, including histopathology, leukocyte infiltration (polymorphonuclear leukocytes/alveoli ratio and myeloperoxidase activity), and lung water content, confirmed that I/R caused significant lung injury. Significant increases in inflammatory molecules (chemokine, cytokine, and prostaglandin E(2) concentrations) and lipid peroxidation (malondialdehyde concentration) confirmed that I/R caused significant inflammation and oxidative stress in rat lungs. MgSO(4), at the dosages of 50 and 100 mg/kg but not 10 mg/kg, attenuated the oxidative stress, inflammation, and lung injury induced by I/R. Moreover, BAY-K8644 reversed the protective effects of MgSO(4).

CONCLUSIONS:

MgSO(4) mitigates lung injury induced by bilateral lower limb I/R in rats. The mechanisms may involve inhibiting the L-type calcium channels.

• Authors: Ming-Chang Kao, Woan-Ching Jan, Pei-Shan Tsai, Tao-Yeuan Wang, Chun-Jen Huang
• Journal: The Journal of surgical research (J Surg Res) Vol. 171 Issue 1 Pg. e97-106 (Nov 2011) ISSN: 1095-8673 [Electronic] United States
• PMID: 21514604 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2011 Elsevier Inc. All rights reserved.

Chemical References

• Calcium Channel Blockers
• Calcium Channels, L-Type
• Nitric Oxide
• Magnesium Sulfate
• Peroxidase
• Ptgs2 protein, mouse
• Cyclooxygenase 2
• Dinoprostone

Topics

• Acute Lung Injury (drug therapy, etiology, metabolism)
• Animals
• Blood Gas Analysis
• Blood Pressure (physiology)
• Calcium Channel Blockers (pharmacology)
• Calcium Channels, L-Type (metabolism)
• Cyclooxygenase 2 (metabolism)
• Dinoprostone (metabolism)
• Extravascular Lung Water (metabolism)
• Heart Rate (physiology)
• Hindlimb (blood supply)
• Magnesium Sulfate (pharmacology)
• Male
• Neutrophils (pathology)
• Nitric Oxide (metabolism)
• Oxidative Stress (drug effects)
• Peroxidase (metabolism)
• Pneumonia (drug therapy, etiology, metabolism)
• Rats
• Rats, Sprague-Dawley
• Reperfusion Injury (complications, metabolism)