BACKGROUND: The heme oxygenase system catalyzes the conversion of heme to free iron, carbon monoxide and bilirubin. This study was purposed to evaluate the effect of the heme oxygenase inhibitor, Tin protoporphyrin IX (SnPPIX) on the hypoxic ischemic brain injury in a neonatal rat.

METHODS: Seven-day old Sprague-Dawley rat pups were used. The rats were divided into two groups; control group (n = 9) and SnPPIX group (n = 6). SnPPIX 50 µmol/kg and the dissolvent were administered respectively intraperitoneally. For hypoxic ischemic brain injury, the right common carotid artery was ligated with 5-0 silk and the rats were put in the moisturized hypoxic gas chamber for 150 minutes. Lipid/N-acetyl aspartate and Lipid/Creatine ratio of ¹H magnetic resonance spectroscopy were evaluated on the 1^st day and the 7^th day after hypoxic ischemic brain injury. All rats were sacrificed 2 weeks after hypoxic ischemic brain injury for morphological study.

RESULTS: There were no statistically significant differences between two groups in the result of MRS and Lip/Cr and Lip/NAA ratio on 1^th day and 7^th day after hypoxic ischemic brain injury. In addition, there was no significant difference in the gross morphological evaluation on the 14^th day.

CONCLUSIONS: Our results suggest that the pretreatment of the Tin protoporphyrin IX does not affect the degree of brain damage which is caused by apoptosis in the model of hypoxic ischemic brain injury in a neonatal rat.