Enzymes and pathways of glucose utilization in bovine adrenal medulla
Enzymes and pathways of glucose utilization in bovine adrenal medulla
复制标题
牛肾上腺髓质葡萄糖利用的酶和途径
DOI：
10.1007/bf00233804
复制
发表时间：
1986
影响因子：
4.3
通讯作者：
M. Miras
中科院分区：
文献类型：
--
作者：
A. Millaruelo;M. R. Sagarral;E. Delicado;M. Torres;M. Miras
用新鲜分离的肾上腺嗜铬细胞研究了牛肾上腺髓质不同代谢途径对葡萄糖的利用。静息细胞中葡萄糖的净利用率为10.5 μ mol × g−1× h−，150%转化为乳酸和丙酮酸，乳酸与丙酮酸的比例为3 ~ 7。27%通过三羧酸循环代谢，3.1%在戊糖磷酸途径中氧化。在培养1小时时，11- 14 Cl葡萄糖和16- 14 Cl葡萄糖产生14 CO2的比例接近2。3.210%的总葡萄糖用于蛋白质合成，1%掺入脂质。离体肾上腺嗜铬细胞呼吸时的氧利用率为18.2 μ mol × g−1× h−1，相当于消耗3.1 μ mol葡萄糖× g−1× h− 1或约30°10的总葡萄糖。测定了牛肾上腺髓质提取液中己糖激酶、烯醇化酶、丙酮酸激酶、乳酸脱氢酶、葡萄糖6-磷酸脱氢酶和6-磷酸葡萄糖酸脱氢酶的活性，分别为1.0、23、40、37、6.0和3.0U/g。己糖激酶活性被鉴定为主要属于同工酶I，具有一些同工酶II。烯醇化酶以α-γ杂种为主。丙酮酸激酶活性对应于同工酶K和M的混合物。乳酸脱氢酶活性对应于同工酶1、2和3，同工酶4和5的比例较小。结果进行了讨论，主要是相对于那些报告的大脑。
Glucose utilization by different metabolic pathways in bovine adrenal medulla has been studied using freshly isolated adrenal chromaffin cells. The rate of net glucose utilization in resting cells was 10.5 μmoles × g−1× h−150% was transformed into lactate and pyruvate, the lactate to pyruvate ratio ranging from 3 to 7. 27% was metabolized through the tricarboxylic acid cycle and 3.1% was oxidized in the pentose phosphate pathway. The ratio of14CO2production from 11-14Cl glucose and 16-14Cl glucose was close to 2 at one hour of incubation. 3.210 of total glucose consumed was used in protein synthesis, and 1% was incorporated into lipids. Oxygen utilization in respiration by isolated adrenal chromaffin cells was 18.2 μmoles × g−1× h−1, corresponding to 3.1 μmoles glucose × g−1× h−1or about 30°10 of total glucose consumed. The activities of hexokinase, enolase, pyruvate kinase, lactate dehydrogenase, glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were assayed in extracts of bovine adrenal medulla, being 1.0, 23, 40, 37, 6.0 and 3.0 U/g respectively. Hexokinase activity was identified as belonging mainly to isoenzyme I, with some isoenzyme II. Enolase was predominantly the αγ hybrid. Pyruvate kinase activity corresponded to a mixture of isoenzymes K and M. Lactate dehydrogenase activity corresponded to isoenzymes 1, 2 and 3, with smaller proportions of isoenzymes 4 and 5. Results are discussed mainly with respect to those reported for the brain.