Armstrong M K, Romsos D R, Leveille G A
J Nutr. 1976 Jul;106(7):884-91. doi: 10.1093/jn/106.7.884.
This study was undertaken to establish the time sequence of lipogenic changes in adipose tissue of rats when converted from ad libitum feeding to meal-eating. Rats were fed a high carbohydrate diet 2 hours/day for 0 to 10 days (meal-eating). The high speed supernatant fraction from homogenized epididymal fat pads was assayed for citrate cleavage enzyme, acetyl CoA carboxylase, fatty acid synthetase and malic enzyme activities. The effects of meal-feeding on in vitro and in vivo rates of fatty acid synthesis in adipose tissue as well as the amounts of glycogen deposited in the adipose tissue were measured. During the first 10 days of meal-feeding, the lipogenic enzyme activities were actually decreased or unchanged in the meal-fed rats but during this time the in vitro and in vivo rates of fatty acid synthesis were progressively increased in the meal-fed rats. Glycogen levels in the adipose tissue of meal-fed rats were greater than the levels in the nibblers. The initial hyperlipogenesis observed in the meal-fed rat appears to be due to changes in substrate uptake by the adipose tissue and/or to alterations in enzyme activation in the adipose tissue rather than to changes in the quantity of enzyme present in the tissue.
本研究旨在确定大鼠从自由采食转换为定时进食时，脂肪组织中脂肪生成变化的时间顺序。大鼠每天定时进食2小时，持续0至10天（定时进食），喂食高碳水化合物饮食。对附睾脂肪垫匀浆的高速上清液部分进行柠檬酸裂解酶、乙酰辅酶A羧化酶、脂肪酸合成酶和苹果酸酶活性的测定。测量了定时进食对脂肪组织中脂肪酸合成的体外和体内速率以及脂肪组织中糖原沉积量的影响。在定时进食的前10天，定时进食大鼠的脂肪生成酶活性实际上降低或未改变，但在此期间，定时进食大鼠的脂肪酸合成体外和体内速率逐渐增加。定时进食大鼠脂肪组织中的糖原水平高于随意进食大鼠。定时进食大鼠中最初观察到的高脂生成似乎是由于脂肪组织对底物摄取的变化和/或脂肪组织中酶激活的改变，而不是由于组织中酶量的变化。
