The impact of burn injury and ethanol on the cytokine network of the mouse hypothalamus: Reproductive implications

Abstract

Nearly 50% of the patients admitted to hospitals for burn injuries have detectable levels of alcohol (EtOH) in their circulation. In fact, EtOH is often a causal factor in their injury. It is well known that EtOH as well as burn injury disrupt function of the hypothalamic–pituitary–gonadal (HPG) axis. The cellular mechanisms by which EtOH and/or burn impacts on the HPG are not entirely understood. In the studies reported here, we tested the hypothesis that these injuries mediated their effects by local hypothalamic inflammation. Young adult male mice were subjected to either a 15% total body surface area, full thickness scald, to EtOH, or to both and compared to appropriate controls. They were sacrificed 48 h later. EtOH and burn, as well as the combined injury, consistently and impressively reduced serum testosterone, while increasing hypothalamic concentrations of all three of the pro-inflammatory cytokines, TNFα, IL-1β, and IL-6. In general, the increases induced by burn were greater than those caused by EtOH and the effect of the combined insult was not additive. Hypothalamic concentrations of LHRH were also increased. The data are consistent with the idea that EtOH and/or burn, as models of critical illness, medicate their hypothalamic suppressive effects via increase in pro-inflammatory cytokines.