离体大鼠心脏对外源性1,6-二磷酸果糖的摄取和利用

UPTAKE AND UTILIZATION OF FRUCTOSE-1,6- DIPHOSPHATE BY ISOLATED RAT HEART

研究外源性１，６－二磷酸果糖（ＦＤＰ）被心肌细胞摄取和利用时的影响因素。在Ｌａｎｇｅｎｄｏｒｆｆ离体心脏灌流装置下，采用４种不同灌流液逆行循环灌流，通过测定灌流液中ＦＤＰ的消耗量和心肌蛋白释出量，结合心脏作功总量，测算心肌细胞摄取、利用ＦＯＰ的情况。结果：在缺氧灌流和无葡萄糖的供氧灌流条件下，ＦＤＰ组的心脏作功总量均明显高于对照组（Ｐ＜０．０５）；循环灌流液中ＦＤＰ的含量分别减少（１６．２±２．８）％和（２０．１±３．７）％；心肌蛋白释出量低于对照组。结论：在缺氧、供能物质缺乏所导致心肌受损等异常条件下，更有利于外源性ＤＤＰ跨膜进入心肌细胞参与细胞的能量代谢。

PURPOSE To evaluate the uptake and utilization of exogenous fructose- l,6-diphosphate(FDP) by isolated rat hearts, and to investigate factors influencing the process of uptaking FDP by myocardium. METHODS A Langendorff heart set up with 4 kinds of perfusate was used. The total mechanical work of heart and the amount of FDP lose in the perfusate were used to estimate the rate of uptake and utilization of FDP by heart cells. RESULTS It was found that infusion of FDP (5 mmol/ L) caused much higher of total mechanical work of heart than control group (P<0.05) in both anoxia and glucose-free perfusions, and the amounts of FDP loss in perfusate were (16.2± 2.8)% and (20. 1± 3.7)% respectively after 40 min recyclecal perfusion. The protein released from heart in glucose-free perfusion was much lower than the control group (P<0.05). CONCLUSIONS The process of crossing-membrane transport of FDP will be facilitated under the conditions of extracellular anoxia and abscence normal energy-production substrate, and then FDP, as a compensable substrate, will take part in the energy metabolism of myocardium.