禁食和禁食再喂食的阉牛脂肪组织中脂肪酸合成及生脂酶的变化

Changes in fatty acid synthesis and lipogenic enzymes in adipose tissue from fasted and fasted-refed steers.

作者信息

Pothoven M A, Beitz D C

出版信息

J Nutr. 1975 Aug;105(8):1055-61. doi: 10.1093/jn/105.8.1055.

DOI:10.1093/jn/105.8.1055

Abstract

Controls of fatty acid synthesis in bovine adipose tissue were investigated. Six Brown Swiss steers were fasted for 8 days and then refed for 56 days. Biopsy samples of backfat adipose tissue were taken during the fasting and refeeding periods. Rates of acetate incorporation into fatty acids (FAS), activities of acetyl CoA carboxylase (CBX), glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and NADP:isocitrate dehydrogenase, and plasma free fatty acids (FFA) and plasma acetate were determined. FAS decreased 60% after 1 day of fasting and 99% after 8 days. FAS did not increase until day 3 of refeeding when energy intake was above maintenance, then returned to normal by 14 days. CBX followed a pattern similar to FAS, except its activity did rise above the control rate during refeeding. Plasma FFA increased 350% and acetate decreased 67% during fasting. After 4 days of refeeding, FFA returned to normal, and acetate increased to 156% of initial concentration, then returned to normal by 21 days. These data suggest that CBX limits FAS in adipose tissue of cattle.

摘要

对牛脂肪组织中脂肪酸合成的调控进行了研究。选取6头瑞士褐牛阉牛，禁食8天，然后再饲喂56天。在禁食期和再饲喂期采集背部脂肪组织的活检样本。测定了乙酸盐掺入脂肪酸（FAS）的速率、乙酰辅酶A羧化酶（CBX）、葡萄糖-6-磷酸脱氢酶、6-磷酸葡萄糖酸脱氢酶和NADP：异柠檬酸脱氢酶的活性，以及血浆游离脂肪酸（FFA）和血浆乙酸盐的含量。禁食1天后FAS下降60%，禁食8天后下降99%。直到再饲喂第3天能量摄入超过维持量时FAS才增加，然后在14天恢复正常。CBX呈现与FAS相似的模式，但其活性在再饲喂期间确实高于对照速率。禁食期间血浆FFA增加350%，乙酸盐减少67%。再饲喂4天后，FFA恢复正常，乙酸盐增加到初始浓度的156%，然后在21天恢复正常。这些数据表明，CBX限制了牛脂肪组织中的FAS。