Endo Y, Jinnai K, Endo M, Fujita K, Kimura F
Department of Physiology, Yokohama City University School of Medicine, Japan.
Stroke. 1990 Oct;21(10):1464-9. doi: 10.1161/01.str.21.10.1464.
We measured local cerebral blood flow over 24 hours in 10 unanesthetized, freely moving rats to determine whether blood flow in the hippocampus fluctuated as a function of time of day. We measured hydrogen clearance at 1-hour intervals using a polyurethane-coated platinum electrode with a 1-mm bare tip implanted in the dorsal hippocampus. Individual rats displayed a wide range of local cerebral blood flow values (from 30 to 100 ml/min/100 g tissue) in a day. In seven of the 10 rats, the overall mean hippocampal blood flow for the dark cycle (7 PM-5 AM) was significantly (p less than 0.001, 0.01, or 0.05) greater than that for the light cycle (6 AM-6 PM), showing an average increase of 20%. Further, the maximum mean hippocampal blood flow at 11 PM in all 10 rats was 42% greater than the minimum at noon. Our study demonstrates for the first time that local cerebral blood flow in the hippocampus shows diurnal variation.
我们在10只未麻醉、自由活动的大鼠身上测量了24小时的局部脑血流量，以确定海马体中的血流量是否随一天中的时间而波动。我们使用一个裸尖端为1毫米、涂有聚氨酯的铂电极，每隔1小时测量一次氢清除率，该电极植入背侧海马体。一天中，每只大鼠的局部脑血流量值范围很广（从30到100毫升/分钟/100克组织）。在10只大鼠中的7只中，黑暗周期（晚上7点至凌晨5点）的海马体总体平均血流量显著（p小于0.001、0.01或0.05）高于光照周期（上午6点至下午6点），平均增加了20%。此外，所有10只大鼠在晚上11点时的海马体平均血流量最大值比中午时的最小值大42%。我们的研究首次证明，海马体中的局部脑血流量存在昼夜变化。
