Department of Physiology, Faculty of Veterinary Medicine, Bursa Uludag University, Bursa, Turkiye.
Department of Physiology, Faculty of Veterinary Medicine, Dokuz Eylül University, Kiraz, İzmir, Turkiye.
Turk J Med Sci. 2024 Mar 27;54(3):598-606. doi: 10.55730/1300-0144.5827. eCollection 2024.
BACKGROUND/AIM: Our recent study revealed that the expression of lipoxygenase (LOX) and cyclooxygenase (COX) enzymes in the hypothalamus is activated by nesfatin-1, leading to the liberation of leukotrienes and prostaglandins (PG), respectively. Moreover, our prior report explained that intracerebroventricular (ICV) nesfatin-1 treatment triggers cardiovascular responses mediated by central LOX and COX enzymes. Building upon our prior reports, the present investigation sought to clarify the role of cardiovascularly active central COX products, such as thromboxane (TX) A2, PGF2α, PGE, and PGD, in orchestrating nesfatin-1-evoked reactions in mean arterial pressure (MAP) and heart rate (HR).
The Sprague Dawley rats, which had guide cannula in the lateral ventricle for intracerebroventricular (ICV) injections and catheter in arteria femoralis for monitoring MAP and HR, were underwent central pretreatment with furegrelate (the TXA2 synthase inhibitor), PGF2α-dimethylamine (PGF2α-DA, the PGF2α receptor antagonist), or AH6809 (the PGE and PGD receptor antagonist), 5 min prior to ICV nesfatin-1 administration. The cardiovascular parameters were observed and recorded for 60 min posttreatment.
Nesfatin-1 induced cardiovascular responses in rats leading to pressor effect in MAP, and tachycardia following bradycardia in HR. Interestingly, ICV furegrelate, PGF2α-DA, or AH6809 pretreatment partially mitigated the cardiovascular effects revealed by nesfatin-1.
The findings illuminate the role of nesfatin-1 in modulating MAP and HR through the central activation of specifically TXA2, PGF2α, PGE, and PGD from COX metabolites. Additionally, the study may also suggest the potential involvement of other central COX or LOX metabolites beyond these COX metabolites in mediating the cardiovascular effects produced by nesfatin-1.
背景/目的:我们最近的研究表明,孤啡肽-1 可激活下丘脑内的脂氧合酶(LOX)和环氧化酶(COX),分别导致白三烯和前列腺素(PG)的释放。此外,我们之前的报告解释了脑室注射孤啡肽-1 会触发中枢 LOX 和 COX 酶介导的心血管反应。基于我们之前的报告,本研究旨在阐明心血管活性中枢 COX 产物,如血栓素(TX)A2、PGF2α、PGE 和 PGD,在调节孤啡肽-1 引起的平均动脉压(MAP)和心率(HR)反应中的作用。
将 Sprague Dawley 大鼠的侧脑室引导套管用于脑室(ICV)注射,股动脉导管用于监测 MAP 和 HR,在给予孤啡肽-1 前 5 分钟,大鼠预先接受 furegrelate(血栓素 A2 合酶抑制剂)、PGF2α-二甲胺(PGF2α-DA,PGF2α 受体拮抗剂)或 AH6809(PGE 和 PGD 受体拮抗剂)的中枢预处理。观察并记录治疗后 60 分钟的心血管参数。
孤啡肽-1 诱导大鼠产生心血管反应,导致 MAP 升高,HR 先出现心动过缓后出现心动过速。有趣的是,ICV furegrelate、PGF2α-DA 或 AH6809 预处理部分减轻了孤啡肽-1 引起的心血管作用。
这些发现阐明了孤啡肽-1 通过中枢激活 COX 代谢物中的特定 TXA2、PGF2α、PGE 和 PGD 来调节 MAP 和 HR 的作用。此外,该研究还表明,在介导孤啡肽-1 产生的心血管作用方面,除了这些 COX 代谢物之外,其他中枢 COX 或 LOX 代谢物也可能参与其中。