摘要
BACKGROUND： Studies have shown that voltage-dependent calcium influx, and enhancement of certain calcium-dependent processes in neurons, is related to aging. OBJECTIVE： To observe changes in intracellular calcium （[Ca^2＋]i） in neurons of aged rats, and to compare with young rats. DESIGN, TIME AND SETTING： A randomized control experiment of neurophysiology was performed at the Central Laboratory of School of Pharmaceutical Science, China Medical University from June to August 2004. MATERIALS： Ten male, healthy, Wistar rats, 19 months old, were selected for the aged group. Ten male, 3-month-old, Wistar rats were selected for the young control group. Fura-2/AM was provided by the Institute of Pharmaceutical Research of Chinese Academy of Medical Sciences, and the F-2000 fluorospectrophotometer was a product of Hitachi, Japan. METHODS： Fluorescence Fura-2 spectrophotometer was used to measure [Ca^2＋]i in acutely dissociated brain cells of aged and young rats. The concentration of extracellular potassium was controlled by adding different volumes of chloridated potassium solution of high concentration. MAIN OUTCOME MEASURES： [Ca^2＋]i in neurons of young and aged rats in the presence of I mmol/L extracellular calcium concentration and 0 mmol/L （resting state）, 5, 10, 20, and 40 mmol/L extracellular potassium. Absolute increase of [Ca^2＋]i in neurons of young and aged rats when extracellular potassium was 5, 10, 20, 40 mmol/L. RESULTS： In the presence of 1 mmol/L extracellular Ca〉 and 0 mmol/L （resting state）, 5, 10, 20, and 40 mmol/L extracellular potassium, [Ca^2＋]i in the neurons of aged rats was significantly less than that in young rats （P 〈 0.05）. However, there was no significant difference in absolute [Ca^2＋]i increase induced by different concentrations of KCI between the aged and the young rats （P 〉 0.05）. CONCLUSION： The overload of [Ca^2＋]i in neurons of aged rats is greater than that of young rats under the same circumstances.
BACKGROUND： Studies have shown that voltage-dependent calcium influx, and enhancement of certain calcium-dependent processes in neurons, is related to aging. OBJECTIVE： To observe changes in intracellular calcium （[Ca^2＋]i） in neurons of aged rats, and to compare with young rats. DESIGN, TIME AND SETTING： A randomized control experiment of neurophysiology was performed at the Central Laboratory of School of Pharmaceutical Science, China Medical University from June to August 2004. MATERIALS： Ten male, healthy, Wistar rats, 19 months old, were selected for the aged group. Ten male, 3-month-old, Wistar rats were selected for the young control group. Fura-2/AM was provided by the Institute of Pharmaceutical Research of Chinese Academy of Medical Sciences, and the F-2000 fluorospectrophotometer was a product of Hitachi, Japan. METHODS： Fluorescence Fura-2 spectrophotometer was used to measure [Ca^2＋]i in acutely dissociated brain cells of aged and young rats. The concentration of extracellular potassium was controlled by adding different volumes of chloridated potassium solution of high concentration. MAIN OUTCOME MEASURES： [Ca^2＋]i in neurons of young and aged rats in the presence of I mmol/L extracellular calcium concentration and 0 mmol/L （resting state）, 5, 10, 20, and 40 mmol/L extracellular potassium. Absolute increase of [Ca^2＋]i in neurons of young and aged rats when extracellular potassium was 5, 10, 20, 40 mmol/L. RESULTS： In the presence of 1 mmol/L extracellular Ca〉 and 0 mmol/L （resting state）, 5, 10, 20, and 40 mmol/L extracellular potassium, [Ca^2＋]i in the neurons of aged rats was significantly less than that in young rats （P 〈 0.05）. However, there was no significant difference in absolute [Ca^2＋]i increase induced by different concentrations of KCI between the aged and the young rats （P 〉 0.05）. CONCLUSION： The overload of [Ca^2＋]i in neurons of aged rats is greater than that of young rats under the same circumstances.
