These findings were also observed in rats and pigs, where the increased plasma levels of KYN, KYNA and 3-HAA occurred during the initial hours following resuscitation and persisted up to 3–5 days following cardiac arrest and KP activation showed an equivalent time course in rats, pigs, and humans, and was significantly related to the severity of post-resuscitation myocardial dysfunction, functional outcome and survival (97). Here, NPPA is linked to cardiac arrest.