Effects of diabetes and fasting on pantothenic acid metabolism in rats.
Effects of diabetes and fasting on pantothenic acid metabolism in rats.
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糖尿病和禁食对大鼠泛酸代谢的影响。
DOI：
10.1152/ajpendo.1981.240.6.e597
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
Neely,JR
中科院分区：
文献类型：
--
作者：
Reibel,DK;Wyse,BW;Berkich,DA;Palko,WM;Neely,JR
研究了禁食和糖尿病对大鼠泛酸（PA）代谢的影响。测定 PA 和辅酶 A (CoA) 的组织水平以及 [14C]PA 摄取和掺入组织 CoA 的速率。禁食和糖尿病都会导致 [14C]PA 摄取速度加快、PA 组织浓度升高、[14C]PA 与 CoA 的结合增加以及肝脏中 CoA 的组织浓度升高。肝脏中PA的浓度接近对照动物中PA的泛酸激酶的Km，并且PA摄取增加可能部分地解释了尽管组织PA水平升高但[14C]PA掺入CoA的增加。在心肌中，在禁食动物和糖尿病动物中，[14C]PA 掺入 CoA 的增加和 CoA 水平的增加与 PA 摄取减少和组织 PA 水平降低相关，这表明 CoA 合成不受该组织中底物可用性的控制。糖尿病动物骨骼肌对[14C]PA的摄取也减少。这些数据表明组织对 PA 的吸收受到代谢或激素的控制。肌肉摄取减少和肝脏摄取增加可能代表将肌肉中存在的大量体内 PA 储存转移到肝脏的机制，而肝脏中内源性 PA 浓度通常较低。此外，禁食和糖尿病都会导致尿 PA 排泄减少，这一发现可能代表了在这些条件下保存全身 PA 的调节机制。
The effects of fasting and diabetes on pantothenic acid (PA) metabolism were studied in rats. Tissue levels of PA and coenzyme A (CoA) and rates of [14C]PA uptake and incorporation into tissue CoA were determined. Both fasting and diabetes resulted in accelerated rates of [14C]PA uptake, higher tissue concentrations of PA, increased incorporation of [14C]PA into CoA, and elevated tissue concentrations of CoA in the liver. The concentration of PA in liver was near the Km of pantothenate kinase for PA in control animals, and increased PA uptake may, in part, account for the increased [14C]PA incorporation into CoA though an elevation in tissue PA levels. In cardiac muscle, increased [14C]PA incorporation into CoA and increased CoA levels were associated with reduced PA uptake and reduced tissue PA levels in both fasting and diabetic animals, suggesting that CoA synthesis is not controlled by substrate availability in this tissue. Uptake of [14C]PA by skeletal muscle was also reduced in diabetic animals. These data suggest that PA uptake by tissues is under metabolic or hormonal control. Decreased uptake by muscle and increased uptake by liver may represent a mechanism for shifting large body stores of PA present in muscle to the liver in which endogenous PA concentrations are normally low. In addition, both fasting and diabetes resulted in decreased urinary PA excretion, a finding that may represent a regulatory mechanism to conserve whole-body PA under these conditions.