N-methyl-D-aspartate (NMDA) receptors were found to be dysfunctional in hypertensive rats. Methyl palmitate (MP) has been shown to diminish the nicotine-induced increase in blood flow in the brainstem. The aim of this study was to determine how MP modulated NMDA-induced increased regional cerebral blood flow (rCBF) in normotensive (WKY), spontaneously hypertensive (SHR), and renovascular hypertensive (RHR) rats. The increase in rCBF after the topical application of experimental drugs was measured using laser Doppler flowmetry. Topical NMDA application induced an MK-801-sensitive increase in rCBF in anesthetized WKY rats, which was inhibited by MP pretreatments. This inhibition was prevented by pretreatment with chelerythrine (a PKC inhibitor). The NMDA-induced increase in rCBF was also inhibited by the PKC activator in a concentration-dependent manner. Neither MP nor MK-801 affected the increase in rCBF induced by the topical application of acetylcholine or sodium nitroprusside. Topical application of MP to the parietal cortex of SHRs, on the other hand, increased basal rCBF slightly but significantly. MP enhanced the NMDA-induced increase in rCBF in SHRs and RHRs. These results suggested that MP had a dual effect on the modulation of rCBF. MP appears to play a significant physiological role in CBF regulation.

中文翻译：

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棕榈酸甲酯调节 NMDA 诱导的高血压大鼠脑充血。

研究发现高血压大鼠的 N-甲基-D-天冬氨酸 (NMDA) 受体功能失调。棕榈酸甲酯（MP）已被证明可以减少尼古丁引起的脑干血流量增加。本研究的目的是确定 MP 如何调节 NMDA 诱导正常血压 (WKY)、自发性高血压 (SHR) 和肾血管性高血压 (RHR) 大鼠的局部脑血流量 (rCBF) 增加。使用激光多普勒血流计测量局部应用​​实验药物后 rCBF 的增加。局部 NMDA 诱导麻醉 WKY 大鼠中 MK-801 敏感的 rCBF 增加，而 MP 预处理可抑制这种增加。通过用白屈菜红碱（PKC 抑制剂）进行预处理可以防止这种抑制。NMDA 诱导的 rCBF 增加也被 PKC 激活剂以浓度依赖性方式抑制。MP 和 MK-801 均不影响局部应用乙酰胆碱或硝普钠引起的 rCBF 增加。另一方面，局部应用 MP 至 SHR 的顶叶皮层，可轻微但显着地增加基础 rCBF。MP 增强了 NMDA 诱导的 SHR 和 RHR 中 rCBF 的增加。这些结果表明 MP 对 rCBF 的调节具有双重作用。MP 似乎在 CBF 调节中发挥着重要的生理作用。