The 4 VO model were chosen
because it is the most used model that resembles a human cardiac arrest where the blood supply in the brain is almost depleted. The outcomes are neurological damage, loss of memory, convulsions and coma. During clamping, the animals were awake and spontaneously ventilating. During both surgeries, rectal temperature was monitored and maintained at 36.5–37.5 °C with a rectal thermistor and heat lamp until recovery from anesthesia. Sham operated animals were subjected to the same anesthesia and surgical procedures as animals subjected to global ischemia, except the carotid arteries were not occluded (Netto et al., 1993). Animals that failed to show complete loss of the righting reflex and pupillary dilatation (from 2 min after occlusion has initiated until the end of occlusion); find more animals that exhibited obvious behavioral manifestations (abnormal vocalization when handled, convulsions, hyperactivity etc.) were excluded from the experiment; and
animals with loss of greater than 20% of body weight by 3–7 day after ischemia. There were 5 deaths due to respiratory arrest; 11 other rats were excluded from the study because they failed to show neurological signs of ischemia (no loss of consciousness or incomplete dilation of the pupils during occlusion). One hour before ischemia or 0 h, 3 h, 6 h or 24 h after ischemia animals received intracerebroventricular this website (icv) injections into the right lateral ventricle of 20 μg of coumestrol (Sigma) (diluted in 100% dimethylsufoxide) (DMSO; Sigma), 20 μg STK38 of 17 β-estradiol (diluted in 0.9% saline solution containing 10% DMSO) or 50 μg of ICI
182,780 (Sigma), in a volume of 2 μl. Control animals were infused with vehicle (100% DMSO). The dose of 20 μg was chosen based on previous studies with estrogen-like compounds (Azcoitia et al., 1999;Picazo et al., 2003; Callier et al., 2001, Bryant et al., 2005 and Toung et al., 2000) with similar proprieties and actions in the central nervous system. Animals also received icv infusion of the broad-spectrum antagonist ICI 182,780 or vehicle into the lateral ventricle. The administration of 50 μg was done 10 min prior to the other drugs administration. For the peripheral administration, a dose of 20 μg/kg of coumestrol was injected intracardiaclly one hour before the ischemic insult. Coumestrol was diluted in 100% dimethylsufoxide (DMSO; sigma) in a volume of 300 μl. In the first experiment, rats were positioned in a stereotaxic apparatus and icv injections performed under halothane anesthesia either 1 h before ischemia or 0 h, 3 h, 6 h or 24 h after ischemia, The position of the right lateral ventricle was calculated based on the position of bregma: 0.92 mm posterior to bregma, 1.2 mm lateral to bregma, 3.