Vorn Rany, Yoo Hae Young
Chung-Ang University Red Cross College of Nursing, Seoul 06974, Korea.; Chung-Ang University Graduate School, Seoul 06974, Korea.
Chung-Ang University Red Cross College of Nursing, Seoul 06974, Korea.
Korean J Physiol Pharmacol. 2017 Jan;21(1):91-97. doi: 10.4196/kjpp.2017.21.1.91. Epub 2016 Dec 21.
Hyperglycemia is associated with an increased risk of cardiovascular diseases. It has been demonstrated that chronic exposure to high glucose impaired endothelial functions. However, specific effects of short-term exposure to high glucose on vascular reactivity are controversial. Moreover, the combined effects of other metabolic substrates such as free fatty acids (FFA) on vascular reactivity remain poorly understood. Here we investigate the effects of short-term exposure to high glucose with or without other metabolic substrates including FFAs termed "nutrition full" (NF) solution, on mesenteric (MA) and deep femoral arteries (DFA) of rats. Arterial ring segments were mounted in a double-wire myograph. Contraction in response to phenylephrine (PhE) was determined in control (5 mM) and high glucose (23 mM, HG) environments over a 30 min period. In both arteries, PhE-inducedvasocontraction was enhanced by pre-incubation of HG solution. A combined incubation with HG and palmitic acid (100 µM) induced similar sensitization of PhE-contractions in both arteries. In contrast, high K-induced contractions were not affected by HG. Interestingly, pre-incubation with NF solution decreased PhE-induced contraction in MA but increased the contraction in DFA. In NF solution, the HG-induced facilitation of PhE-contraction was not observed in MA. Furthermore, the PhE-induced contraction of DFA was attenuated by HG in NF solution. Our results demonstrate that the sensitization of PhE-induced arterial contraction by HG is differentially affected by other metabolic substrates. The conversation of skeletal arterial contractility by HG in NF solution requires careful interpretation of the previous in vitro studies where only glucose is included in physiological salt solutions. Further studies are required to elucidate the mechanism underlying the inconsistent effect of NF solution on MA and DFA.
高血糖与心血管疾病风险增加相关。已证实长期暴露于高糖环境会损害内皮功能。然而，短期暴露于高糖对血管反应性的具体影响仍存在争议。此外，其他代谢底物如游离脂肪酸（FFA）对血管反应性的联合作用仍知之甚少。在此，我们研究了短期暴露于高糖以及有无包括FFA在内的其他代谢底物（称为“营养充足”（NF）溶液）对大鼠肠系膜动脉（MA）和股深动脉（DFA）的影响。将动脉环段安装在双丝肌动描记器上。在对照（5 mM）和高糖（23 mM，HG）环境中，在30分钟内测定对去氧肾上腺素（PhE）的收缩反应。在两条动脉中，HG溶液预孵育均可增强PhE诱导的血管收缩。HG与棕榈酸（100 µM）联合孵育在两条动脉中均诱导出类似的PhE收缩致敏作用。相比之下，高钾诱导的收缩不受HG影响。有趣的是，NF溶液预孵育可降低MA中PhE诱导的收缩，但增加DFA中的收缩。在NF溶液中，MA中未观察到HG诱导的PhE收缩促进作用。此外，在NF溶液中，HG可减弱DFA中PhE诱导的收缩。我们的结果表明，HG对PhE诱导的动脉收缩的致敏作用受到其他代谢底物的不同影响。在NF溶液中，HG对骨骼肌动脉收缩性的改变需要对以往仅在生理盐溶液中包含葡萄糖的体外研究进行仔细解读。需要进一步研究以阐明NF溶液对MA和DFA产生不一致作用的潜在机制。
