Dept. of Experimental and Clinical Physiology, Medical Univ. of Warsaw, Warsaw, Poland.
Am J Physiol Regul Integr Comp Physiol. 2010 Mar;298(3):R672-80. doi: 10.1152/ajpregu.00543.2009. Epub 2009 Dec 30.
The present study was designed to determine the role of central vasopressin 1 receptors (V(1)R) in the regulation of cardiovascular parameters in chronically stressed infarcted rats and sham-operated rats under resting conditions and during exposure to acute alarming stress. The experiments were performed on four groups of conscious sham-operated and four groups of infarcted rats subjected to intraventricular infusion of either vehicle or a V(1)R antagonist (V(1)RANT). Two groups of infarcted and two groups of sham-operated rats were subjected to mild chronic stressing. Mean arterial blood pressure (MABP) and heart rate (HR) were determined under resting conditions and after exposure to acute stress (air jet). During vehicle infusion, MABP and HR increases in response to acute stress in the infarcted rats not subjected to chronic stress, and in the infarcted and sham-operated chronically stressed rats, were significantly greater than in the sham-operated rats not exposed to chronic stress. However, MABP and HR responses to acute stress in the chronically stressed infarcted rats and chronically stressed sham-operated rats did not differ. V(1)RANT abolished differences in cardiovascular responses to acute stress between the experimental groups. Resting cardiovascular parameters were not affected by any of the experimental treatments. It is concluded that chronic stressing enhances the pressor and tachycardic responses to acute stress in the sham-operated rats but does not further intensify these responses in infarcted rats.The results provide evidence that central V(1)Rs are involved in potentiation of cardiovascular responses to acute stress in chronically stressed rats, infarcted rats, and chronically stressed infarcted rats.
本研究旨在确定中枢血管加压素 1 型受体（V(1)R）在慢性应激性梗死大鼠和假手术大鼠在休息状态下和急性应激暴露期间调节心血管参数中的作用。实验在四组清醒的假手术大鼠和四组接受脑室输注载体或 V(1)R 拮抗剂（V(1)RANT）的梗死大鼠中进行。两组梗死大鼠和两组假手术大鼠接受轻度慢性应激。在休息状态下和急性应激（空气喷射）后测定平均动脉血压（MABP）和心率（HR）。在未接受慢性应激的梗死大鼠以及梗死和假手术慢性应激大鼠中，急性应激时 V(1)RANT 输注后，MABP 和 HR 的增加明显大于未暴露于慢性应激的假手术大鼠。然而，慢性应激性梗死大鼠和慢性应激性假手术大鼠的急性应激的 MABP 和 HR 反应没有差异。V(1)RANT 消除了急性应激对各实验组心血管反应的差异。休息时的心血管参数不受任何实验处理的影响。研究结果表明，慢性应激增强了假手术大鼠对急性应激的升压和心动过速反应，但不会进一步增强梗死大鼠的这些反应。研究结果提供了证据，表明中枢 V(1)R 参与了慢性应激大鼠、梗死大鼠和慢性应激性梗死大鼠对急性应激的心血管反应的增强。
