Dose-related effects of dexmedetomidine on sepsis-initiated lung injury in rats

Background: Sepsis is one of the leading causes of death in intensive care units. Dexmedetomidine is a sedative agent with anti-inflammatory properties. This study is designed to differentiate the impact of two different doses of dexmedetomidine on lung injury induced by sepsis. Methods: Adult male Wistar rats were randomly divided into four groups: sham (n = 6), control (n = 12), 5DEX (n = 12), and 10DEX (n = 12). Cecal ligation puncture (CLP) was applied for sepsis initiation. The 5DEX group received 5 μg.kg-1.h-1 and the 10DEX group received 10 μg.kg-1.h-1 dexmedetomidine intravenous infusions for a 1-hour period. Six hours after CLP, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and intercellular adhesion molecule-1 (ICAM-1) levels were analyzed in blood samples. Twenty-four hours after CLP, lung samples from the remaining rats were collected for the measurement of myeloperoxidase (MPO) activity, histological examination, and TdT- (terminal deoxynucleotidyl transferase) mediated fluorescent-dUTP labeling staining for apoptosis detection. Results: Serum cytokine release, MPO activity, and apoptosis in the lung were significantly increased in the CLP group compared with the sham and dexmedetomidine groups (p