A model for acute carbon monoxide poisoning in conscious rats

A model for acute carbon monoxide poisoning in conscious rats. Undersea Hyperbaric Med 1996; 23(2):99-106. - These experiments were designed to establish an animal model of acute carbon monoxide (CO) poisoning in awake habituated rats. On the day before exposure, under a brief anesthesia, a Levine preparation (unilateral common carotid artery occlusion) was performed on group 1 (n=8) and 2 (n = 28), but not on group 3 rats (n = 8). Group 1 rats were exposed to air as control. Groups 2 and 3 rats were exposed to 0.27% CO in air for 60 min [carboxyhemoglobin (HbCO) = 70%] followed by a 2-day recovery in air. The Levine preparation per se did not induce any detectable physiologic effects on group 1 rats. Identical cardiovascular and metabolic responses to CO occurred in groups 2 and 3. After the CO exposure, all group 3 rats lived for 2 days with normal neurologic index (NI). In group 2 (n = 25 post-CO), 84% of the rats showed increased NI and edema of the ipsilateral cerebral hemisphere, and 76% of the rats died 8.7 ± 1.7 h after the CO exposure. NI correlated with the brain edema (r_s =0.748, P 0.001) and inversely correlated with the survival time after the CO exposure (r_s = -0.777, P < 0.001). We therefore may conclude that exposure of the Levine-prepared rats to 0.27% CO in air for 60 min will provide a valuable model for testing of different treatments for CO poisoning.