REGULATION OF CHOLESTEROL-SYNTHESIS IN THE LIVER AND MAMMARY-GLAND OF THE LACTATING RAT
REGULATION OF CHOLESTEROL-SYNTHESIS IN THE LIVER AND MAMMARY-GLAND OF THE LACTATING RAT
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DOI：
10.1042/bj2120843
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发表时间：
1983-01-01
影响因子：
4.1
通讯作者：
WILLIAMSON, DH
中科院分区：
文献类型：
--
作者：
GIBBONS, GF;PULLINGER, CR;WILLIAMSON, DH
在1000 - 1430 h之间处死的大鼠泌乳乳腺中3-羟基-3-甲基戊二酰-CoA还原酶（HMG-CoA还原酶; EC 1.1.1.34）的活性是相同动物肝脏中的2-3倍。相反，在体内注射3H_2O后，3 H在腺体胆固醇中的出现率远低于在肝脏中的出现率。在未泌乳和非泌乳动物的乳腺中，HMG-CoA还原酶的活性<泌乳腺的10%。泌乳期乳腺HMG-CoA还原酶活性午夜显著低于中午（P < 0.005），且与肝酶活性呈负相关。3 H掺入腺体胆固醇中没有相应的变化。禁食6 h对泌乳期乳腺HMG-CoA还原酶活性无影响，但使肝脏HMG-CoA还原酶活性显著降低（P < 0.005）。哺乳期大鼠饥饿24小时后，两种器官中的酶活性均显著降低（P <0.005）。3 H2O在体内掺入两种器官胆固醇的速率也显著下降（肝脏，P < 0.05;腺体，P < 0.005）。给哺乳期动物提供高脂肪可口的饮食和食物导致乳腺中HMG-CoA还原酶活性下降，但肝脏中没有。腺体的这种减少并不伴随着胆固醇合成表观速率的相应下降。
The activity of 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase; EC 1.1.1.34) in the lactating mammary gland of rats killed between 1000 and 1430 h was 2-3 times that in the livers of the same animals. In contrast, after injection of 3H2O in vivo, the rate of appearance of 3H in the cholesterol of the gland was much lower than that in the liver. In the mammary gland of virgin and non-lactating animals, the activity of HMG-CoA reductase was < 10% of that of the lactating gland. The activity of HMG-CoA reductase in the lactating mammary gland was significantly (P < 0.005) lower at midnight than at mid-day, and appeared to show an inverse relationship to the activity of the liver enzyme. There was no corresponding change in the incorporation of 3H into the gland cholesterol. Withdrawal of food for 6 h had no effect on the activity of HMG-CoA reductase in the lactating mammary gland, but resulted in a significant decrease (P < 0.005) in that of the liver. Starvation of lactating rats for 24 h produced a significant decrease (P < .005) in the activity of th enyzme in both organs. There was also a significant decline in the rate at which 3H2O was incorporated in vivo into the cholesterol of both organs (liver, P < 0.05; gland, P < 0.005). Giving a high-fat palatable diet together with chow to lactating animals led to a decline in HMG-CoA reductase activity in the mammary gland, but not in liver. This decrease in the gland was not acompanied by a corresponding decline in the apparent rate of cholesterol synthesis.