Attenuation of Acute Lung Inflammation and Injury by Whole Body Cooling in a Rat Heatstroke Model

Abstract

Whole body cooling is the current therapy of choice for heatstroke because the therapeutic agents are not available. In this study, we assessed the effects of whole body cooling on several indices of acute lung inflammation and injury which might occur during heatstroke. Anesthetized rats were randomized into the following groups and given (a) no treatment or (b) whole body cooling immediately after onset of heatstroke. As compared with the normothermic controls, the untreated heatstroke rats had higher levels of pleural exudates volume and polymorphonuclear cell numbers, lung myloperoxidase activity and inducible nitric oxide synthase expression, histologic lung injury score, and bronchoalveolar proinflammatory cytokines and glutamate, and PaCO2. In contrast, the values of mean arterial pressure, heart rate, PaO2, pH, and blood HCO3− were all significantly lower during heatstroke. The acute lung inflammation and injury and electrolyte imbalance that occurred during heatstroke were significantly reduced by whole body cooling. In conclusion, we identified heat-induced acute lung inflammation and injury and electrolyte imbalance could be ameliorated by whole body cooling.

Melatonin reduces acute lung inflammation, edema, and hemorrhage in heatstroke rats

“…An overproduction of TNF-α is also noted in endotoxin-induced lung inflammation [35] . Both our previous [6] and present results confirm that the inflammatory process (eg, heat-induced acute pleurisy) leads to the overproduction of pro-inflammatory cytokines, such as TNFalpha, IL-1β, and IL-6, in the BALF. Our results further show that the increased BALF levels of both IL-1β and TNF-α during experimental heatstroke can be reduced by melatonin.…”

“…More than three quarters of studied heatstroke patients develop multiple organ dysfunction, the most common of which is acute respiratory distress syndrome clinically manifested as inflammatory lung injury of very rapid onset [4] . Indeed, acute lung inflammation and injury can be induced in a rat heatstroke model [5,6] .…”

Exciting Times beyond the Brain: Metabotropic Glutamate Receptors in Peripheral and Non-Neural Tissues

“…Other disorders involving inflammation are also associated with L-glutamate extravasation toward the affected region: in models of acute lung injury such as heat-induced lung inflammation and hyperoxia-induced neonatal lung inflammation, tissue damage is accompanied by the release of high levels of glutamate (Wang et al, 2009;Yang et al, 2009). Likewise, synovial fluid isolated from the knee joints in patients suffering from rheumatoid arthritis and animal models of arthritis contain increased L-glutamate levels (Flood et al, 2007).…”

Mild Hypothermia Attenuates Circulatory and Pulmonary Dysfunction During Experimental Endotoxemia*

“…The hypometabolic state induced by MH reduced systemic oxygen demand and improved SvO 2 during experimental myocardial infarction and cardiogenic shock in pigs (13,14). MH further improved survival in rodent models of sepsis (15,16) and attenuated lung injury after endotoxin and heatshock exposure (17,18) in rats.…”