Abstract: Ketamine, a multimodal dissociative anesthetic, produces powerful analgesia at subanesthetic doses in traumatically injured patients. As ketamine does not induce respiratory depression or hemodynamic instability, the Committee on Tactical Combat Casualty Care for the US military recommends the use of subanesthetic doses of ketamine for acute pain management (Butler et al., 2014). Additionally, ketamine may have immunomodulatory effects after injury at subanesthetic doses, mediating the balance of pro- and anti-inflammatory processes (Loix et al., 2011; De Kock et al., 2013). The majority of preclinical studies have examined the immunomodulatory effects of ketamine using only male animals, leaving the issue of sex as a biological variable unanswered. Therefore, in a recent study, we investigated the effects of subanesthetic doses of an intravenous (IV) ketamine infusion (0, 10, and 40 mg/kg, 2 hours) on inflammatory cytokine levels in both male and female Sprague-Dawley rats (Spencer et al., 2022). Using rats with indwelling jugular venous catheters, we were able to measure time-dependent changes in plasma cytokine levels following the IV ketamine infusion. This is a significant contribution to the scientific community due to the growing interest in how sex-related differences may play a role in immune function. Moreover, we tested IV ketamine in a non-inflammatory condition, which has not been well characterized previously. Due to the basal immune response differences between males and females (Klein and Flanagan, 2016), examining ketamine effects in a non-inflammatory condition lays the groundwork for future studies utilizing injured or inflammatory conditions with ketamine administration in male and female animals.