Neuromotor deficits and altered physiological responses to repeated exertional heat stroke exposures in mice.

Exertional heat stroke (EHS) is a life-threatening illness that can lead to negative health outcomes. Using a "severe" preclinical mouse model of EHS, we tested the hypotheses that one EHS exposure results in altered susceptibility to a subsequent EHS and reduced neuromotor performance. Female C57BL/6 mice underwent two protocols, 2 wk apart, either an EHS trial (EHS) or a sham exercise control trial (EXC).

Exertional heat stroke leads to concurrent long-term epigenetic memory, immunosuppression and altered heat shock response in female mice.

Key Points: Exposure to exertional heat stroke (EHS) has been linked to increased long-term decrements of health. Epigenetic reprogramming is involved in the response to heat acclimation; however, whether the long-term effects of EHS are mediated by epigenetic reprogramming is unknown. In female mice, we observed DNA methylation reprogramming in bone marrow-derived (BMD) monocytes as early as 4 days of recovery from EHS and as late as 30 days compared with sham exercise controls.

Skeletal Muscle Interleukin-6 Contributes to the Innate Immune Response in Septic Mice.

Interleukin-6 (IL-6) is a major cytokine released by skeletal muscle. Although IL-6 plays complex but well-known roles in host defense, the specific contribution of skeletal muscle IL-6 to innate immunity remains unknown. We tested its functional relevance by exposing inducible skeletal muscle IL-6 knockdown (skmIL-6KD) mice to a cecal slurry model of polymicrobial peritonitis and compared responses to strain-matched controls and skeletal muscle Cre-matched controls at 3, 6, and 12 h postinfection.

Effects of Ibuprofen during Exertional Heat Stroke in Mice.

Unlabelled: Intestinal injury is one of the most prominent features of organ damage in exertional heat stroke (EHS). However, whether damage to the intestine in this setting is exacerbated by ibuprofen (IBU), the most commonly used nonsteroidal anti-inflammatory drug in exercising populations, is not well understood.

Purpose: We hypothesized that IBU would exacerbate intestinal injury, reduce exercise performance, and increase susceptibility to heat stroke.

Osmolality Selectively Offsets the Impact of Hyperthermia on Mouse Skeletal Muscle .

Hyperthermia and dehydration can occur during exercise in hot environments. Nevertheless, whether elevations in extracellular osmolality contributes to the increased skeletal muscle tension, sarcolemmal injury, and oxidative stress reported in warm climates remains unknown. We simulated osmotic and heat stress, , in mouse limb muscles with different fiber compositions.