School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM, Pulau Pinang, Malaysia.
Acta Neurol Belg. 2010 Mar;110(1):57-64.
Obesity is intimately associated with hypertension; increases in blood pressure are closely related to the magnitude of weight gain. The present study aims to determine whether the excitatory amino acid input to rostral ventrolateral medulla (RVLM) contributes to elevated blood pressure in rats with diet-induced obesity. Male Sprague-Dawley rats weighing 280 to 300 grams were fed with a low-fat diet (10% kcal from fat) or moderately high-fat diet (32% kcal from fat) for 16 weeks. At week 16, rats on the moderate high-fat diet were segregated into obesity-prone and obesity-resistant rats based on body weight distribution. Baseline mean arterial pressure (MAP) was significantly higher in obesity-prone rats as compared to obesity-resistant and rats on a low-fat diet. Bilateral injection of kynurenic acid (KYN) (40 nM) into the RVLM of the obesity-prone rats reduced MAP to levels significantly different from those observed in rats on a low-fat diet and obesity-resistant rats (no change in MAP). At a lower concentration (4 nM), KYN injection did not produce any change in MAP in any group. The results obtained suggest that excitatory amino acid input to the RVLM does contribute to the development of hypertension in rats with diet-induced obesity.
肥胖与高血压密切相关；血压升高与体重增加的幅度密切相关。本研究旨在确定兴奋型氨基酸对延髓头端腹外侧区（RVLM）的输入是否导致饮食诱导肥胖大鼠的血压升高。雄性 Sprague-Dawley 大鼠体重 280 至 300 克，给予低脂饮食（10%的热量来自脂肪）或中高脂肪饮食（32%的热量来自脂肪）喂养 16 周。在第 16 周，根据体重分布，将中高脂肪饮食组的大鼠分为肥胖易感组和肥胖抵抗组。肥胖易感大鼠的基础平均动脉压（MAP）明显高于肥胖抵抗组和低脂饮食组大鼠。将犬尿氨酸（KYN）（40 nM）双侧注入肥胖易感大鼠 RVLM 后，MAP 降低至与低脂饮食和肥胖抵抗大鼠观察到的水平显著不同（MAP 无变化）。在较低浓度（4 nM）下，KYN 注射在任何组中均未引起 MAP 变化。所得结果表明，兴奋型氨基酸对 RVLM 的输入确实有助于饮食诱导肥胖大鼠高血压的发生。
