Long-term evaluation of granulocyte-colony stimulating factor on hypoxic-ischemic brain damage in infant rats

Purpose: Hypoxia-ischemia (HI), as a major cause of fetal brain damage, has long-lasting neurological implications. Therefore, therapeutic interventions that attenuate the neuropathological outcome of HI while also improving the neurofunctional outcome are of paramount clinical importance. The aim of this study was to investigate the long-term functional and protective actions of granulocyte-colony stimulating factor (G-CSF) treatment in an experimental model of cerebral HI. Methods: Postnatal day-7 Sprague-Dawley rats were subjected to HI surgery, which entailed ligation of the right common carotid artery followed by 2 h of hypoxia (8% O2). Treatment consisted of subcutaneous injection of G-CSF at 1 h after hypoxia followed by an additional one injection per day for 5 days (6 total injections) or for 10 days (11 total injections). Animals were euthanized 5 weeks post-insult for extensive evaluation of neurological deficits and assessment of brain, spleen, heart, and liver damage. Results: G-CSF treatment promoted somatic growth and prevented brain atrophy and underdevelopment of the heart. Moreover, reflexes, limb placing, muscle strength, motor coordination, short-term memory, and exploratory behavior were all significantly improved by both G-CSF dosing regimens. Conclusions: Long-term neuroprotection afforded by G-CSF in both morphological and functional parameters after a hypoxic-ischemic event in the neonate provides a rationale for exploring clinical translation. © 2010 Copyright jointly held by Springer and ESICM.