Anterior Neck Approach for 4-vessel Occlusion in Rats: A Study for Immunohistological Changes and the Effects of Aminoguanidine on Neuronal Cell Death in the Hippocampus

ABSTRACT

BACKGROUND: Clinically relevant cerebral ischemia is encountered most frequently as a cardiac arrest or as single or multiple occlusions of the intracranial or extracranial cerebral arteries. Yamaguchi et al. has introduced a one-stage anterior approach to occlude the common carotid arteries (CCAs) and vertebral arteries (VAs). METHODS: We used a 2-stage anterior approach for producing transient global ischemia by 4-vessel occlusion (4-VO). Four to five days after electrocauterization of two VAs using the anterior neck approach, two CCAs were clipped for 10 min under anesthesia. Aminoguanidine (100 mg/kg) was administered intraperitoneally immediately after 4-VO, and then twice a day for three consecutive days. Cresyl violet staining and immunohistochemical analysis for the expression of GFAP, CD11b, nitrotyrosine, iNOS, and Bax were performed, using brain slices obtained from the rats that were sacrificed 1, 3, 5 and 7 days after reperfusion. RESULTS: Aminoguanidine reduced neuronal cell death in the CA1 region of the hippocampus. Expression of GFAP, CD11b, nitrotyrosine, iNOS, and Bax were significantly increased in the CA1 region of the hippocampus three days after 4-VO. CONCLUSIONS: We believe that modified 4-VO is a good method to study transient forebrain ischemia as it is simple and inexpensive to perform and can be utilized without stereotaxis, a pivoting dissection microscope, EEG, a laser flowmeter or the use of Mongolian gerbils.