Lipopolysaccharide-induced fever alters Hering-Breuer reflex in anesthetized rats

摘要

The aim of the study was to test the hypothesis that control of breathing via Hering-Breuer reflex (HB) is influenced by lipopolysaccharide (LPS)-induced fever in rats. Animals were injected intraperitoneally with LPS and control group with an equivalent volume of saline. HB reflex was elicited by inflations of the lungs followed by occlusion of the airways under control of esophageal pressure. Duration of HB reflex (T-apnoe) was continuously reduced as body temperature rose during experiment. Compared to normothermic controls, animals with fever had significant shortening of T-apnoe at 240 min and 300 min after LPS administration. Fever was further accompanied by a reduction in the strength of HB reflex (inhibitory ratio, IR). In comparison with controls, significant decrease of IR was observed at 300 min after LPS injection. Conclusion: altered neural control of breathing demonstrated by decreased power of Hering-Breuer inflation reflex in conditions of LPS-induced fever may facilitate thermal tachypnoea and/or play a role in the origin of respiratory instability accompanying febrile response