AIM: To study the effect of mild hypothermia on energy metabolism and hydroxyl radical production as well as delayed neuronal death (DND) in hippocampus during cerebral ischemia/reperfusion in gerbils. METHODS: Forebrain ischemia was induced by occluding bilateral common carotid arteries with aneurysm clamps for 10 min in gerbils. The DND in hippocampal CA1 sector was assessed by histological examination, and hydroxyl radical, ATP (adenosine triphosphate), ADP (adenosine diphosphate),AMP (adenosine monophosphate) levels were determined by high performance liquid chromatography with electrochemical or ultraviolet detection. RESULTS: The number of survival neuronal in hippocampal CA1 sector in mild hypothermia + I/R group was more than that in I/R group after ischemia/reperfusion 96 h. The content of 2,3-DHBA (2,3- dihydroxybenzoic acid) in hippocampus in I/R group was much higher than those in sham operation and mild hypothermia + I/R group after reperfusion 6 h (P

AIM: To study the effect of hypertensive arteriosclerosis on cerebral blood flow autoregulation (CBFA), and to introduce a new method to measure the lower limit. METHODS: The blood velocities and blood pressure was recorded simultaneously and the curves of CBFA were analyzed and classified into classical and non-classical pattern. The lower limit were determined by clinical closing pressure (CCP) and the curve CBFA. RESULTS: When the blood pressure was decreasing, the classical and non-classical pattern of the cerebral blood flow autoregulation were 25% and 75% respectively in normal SD rats, while they were 40.55% and 54.45% respectively in renovascular hypertensive rats (RHR). However, when the blood pressure was elevating, the classical and non-classical pattern were 76.47% and 23.53% respectively in SD rats, while they were all classical in RHR. Furthermore, in SD and RHR ras, the lower limits measured by CCP were well in accordance with that measured by CBFA. CONCLUSION: Hypertensive arteriosclerosis could influence the limits and the patterns of cerebral blood flow autoregulation. The lower limit of CBFA can be measured and analyzed by CCP.