Fukagawa K, Gou H M, Wolf R, Tso P
Department of Physiology, Louisiana State University Medical Center, Shreveport 71130.
Am J Physiol. 1994 Nov;267(5 Pt 2):R1385-90. doi: 10.1152/ajpregu.1994.267.5.R1385.
The aim of the present study was to determine if there is a circadian rhythm in serum and lymph apolipoprotein (apo) AIV and what factors determine this rhythm. Male Sprague-Dawley rats with chronic right atrial catheter were housed in a room illuminated from 0600 to 1800. With ad libitum feeding, serum apo AIV concentration showed a circadian rhythm concomitant with the feeding pattern. In 24-h fasted rats, the serum apo AIV concentration maintained a circadian rhythm and was high during the dark. With mesenteric lymph diversion, serum apo AIV concentration diminished and the circadian rhythm was abolished. The lymph flow, lymph apo AIV, cholesterol, triacylglycerol, and phospholipid contents all exhibited the same circadian rhythm in fasting, with the levels higher in the dark. These circadian rhythms were abolished after bile diversion. In conclusion, serum apo AIV in ad libitum-fed and fasted rats exhibits a circadian rhythm governed by lymph apo AIV output. Furthermore, bile was an important determinant of the circadian rhythm of lymph flow, lymph apo AIV, triacylglycerol, cholesterol, and phospholipid output.
本研究的目的是确定血清和淋巴载脂蛋白（apo）AIV是否存在昼夜节律以及哪些因素决定了这种节律。将带有慢性右心房导管的雄性Sprague-Dawley大鼠饲养在06:00至18:00有光照的房间里。在随意进食的情况下，血清apo AIV浓度呈现出与进食模式相伴的昼夜节律。在禁食24小时的大鼠中，血清apo AIV浓度维持昼夜节律且在黑暗期较高。通过肠系膜淋巴分流，血清apo AIV浓度降低且昼夜节律消失。淋巴流量、淋巴apo AIV、胆固醇、三酰甘油和磷脂含量在禁食时均呈现相同的昼夜节律，黑暗期水平更高。胆汁分流后这些昼夜节律消失。总之，随意进食和禁食大鼠的血清apo AIV呈现出由淋巴apo AIV输出所控制的昼夜节律。此外，胆汁是淋巴流量、淋巴apo AIV、三酰甘油、胆固醇和磷脂输出昼夜节律的重要决定因素。
