Fatty acid synthesis in testes of fat-deficient and fat-supplemented rats.
Fatty acid synthesis in testes of fat-deficient and fat-supplemented rats.
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DOI：
10.1093/jn/107.1.79
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发表时间：
1977
期刊：
影响因子：
--
通讯作者：
A. Whorton;J. Coniglio
中科院分区：
文献类型：
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作者：
A. Whorton;J. Coniglio
研究了无脂肪或脂肪补充饮食大鼠睾丸中的脂肪酸合成。脂肪缺乏大鼠的睾丸将睾丸内注射的[1- 14 C]乙酸盐掺入总脂肪酸（主要是棕榈酸）中的量几乎是补充大鼠的两倍。为了确定合成增加的机制，在睾丸匀浆的细胞质部分中测定了以下酶的活性：脂肪酸合成酶、乙酰辅酶A羧化酶[EC 4.1.3.8]、柠檬酸裂解酶[EC www.example.com ]、苹果酸酶[EC 1.1.1.38]和葡萄糖-1-磷酸脱氢酶[EC 1.1.1.49]：6-磷酸葡萄糖酸脱氢酶对[EC 1.1.1.44]。6.4.1.2虽然脂肪酸合成酶的活性确实增加，从脂肪缺乏大鼠的肝脏，相应的睾丸没有观察到变化。两组之间的柠檬酸裂解酶、苹果酸酶或葡萄糖-6-磷酸脱氢酶：6-磷酸葡萄糖酸脱氢酶对的睾丸活性没有差异。然而，细胞质乙酰辅酶A羧化酶的活性在大鼠睾丸中的脂肪缺乏的饮食是1.4倍，高于活性在大鼠睾丸中的补充饮食。脂肪缺乏不影响睾丸微粒体延伸系统的比活性，通过与14 C-丙二酰辅酶A孵育测定。未酯化脂肪酸的浓度较低，在睾丸中的脂肪缺乏补充大鼠相比，表明减少抑制乙酰辅酶A羧化酶在脂肪缺乏大鼠睾丸可能是负责所观察到的增加从头合成棕榈酸。
Fatty acid synthesis was studied in testes of rats fed a fat-free or fat-supplemented diet. Testes of fat-deficient rats incorporated nearly twice as much intratesticularly injected [1-14C]acetate into total fatty acids (primarily into palmitic acid) as did supplemented rats. To determine the mechanism for the increased synthesis, the activities of the following enzymes were determined in the cytoplasmic fraction of testicular homogenates: fatty acid synthetase, acetyl CoA carboxylase [EC 6.4.1.2], citrate-cleavage [EC 4.1.3.8], malic [EC 1.1.1.38], and the glucose-l-phosphate dehydrogenase [EC 1.1.1.49]: 6-phosphogluconate dehydrogenase pair [EC 1.1.1.44]. Although the activity of fatty acid synthetase did increase in livers from fat-deficient rats, no change was observed in corresponding testes. No difference between the two groups could be demonstrated in testicular activity of citrate-cleavage enzyme, malic enzyme, or the glucose-6-phosphate dehydrogenase: 6-phosphogluconate dehydrogenase pair. However, the activity of cytoplasmic acetyl CoA carboxylase in testes of rats fed the fat-deficient diet was 1.4 times higher than the activity in testes of rats fed the supplemented diet. Fat deficiency did not affect the specific activity of the testicular microsomal elongation system, assayed by incubation with 14C-malonyl CoA. The concentration of unesterified fatty acids was lower in testes of the fat-deficient compared to supplemented rats, indicating that decreased inhibition of acetyl CoA carboxylase in the fat-deficient rats testes might have been responsible for the observed increased de novo synthesis of palmitic acid.