Robbins M T, DeBerry J, Ness T J
Department of Anesthesiology, University of Alabama at Birmingham School of Medicine, Birmingham, AL 35294, USA.
Physiol Behav. 2007 Aug 15;91(5):544-50. doi: 10.1016/j.physbeh.2007.04.009.
This study sought to determine whether acute and/or chronic psychological stress produce changes in urinary bladder nociception. Female Sprague-Dawley (SD; low/moderate anxiety) or Wistar-Kyoto (WK; high-anxiety) rats were exposed to either an acute (1 day) or a chronic (10 days) water avoidance stress paradigm or a sham stress paradigm. Paw withdrawal thresholds to mechanical and thermal stimuli and fecal pellet output, were quantified at baseline and after the final stress or sham stress exposure. Rats were then sedated, and visceromotor responses (VMRs) to urinary bladder distension (UBD) were recorded. While acute stress exposure did not significantly alter bladder nociceptive responses in either strain of rats, WK rats exposed to a chronic stress paradigm exhibited enhanced responses to UBD. These high-anxiety rats also exhibited somatic analgesia following acute, but not chronic, stress. Furthermore, WK rats had greater fecal pellet output than SD rats when stressed. Significant stress-induced changes in nociceptive responses to mechanical stimuli were observed in SD rats. That chronic psychological stress significantly enhanced bladder nociceptive responses only in high-anxiety rats provides further support for a critical role of genetics, stress and anxiety as exacerbating factors in painful urogenital disorders such as interstitial cystitis (IC).
本研究旨在确定急性和/或慢性心理应激是否会引起膀胱伤害感受的变化。将雌性斯普拉格-道利大鼠(SD;低/中度焦虑)或威斯塔-京都大鼠(WK;高度焦虑)暴露于急性(1天)或慢性(10天)的避水应激范式或假应激范式。在基线以及最终应激或假应激暴露后,对机械和热刺激的爪部撤离阈值以及粪便颗粒排出量进行量化。然后将大鼠麻醉,并记录对膀胱扩张(UBD)的内脏运动反应(VMRs)。虽然急性应激暴露并未显著改变两种品系大鼠的膀胱伤害感受反应,但暴露于慢性应激范式的WK大鼠对UBD表现出增强的反应。这些高度焦虑的大鼠在急性应激后也表现出躯体镇痛,但慢性应激后未表现出。此外,应激时WK大鼠的粪便颗粒排出量比SD大鼠更多。在SD大鼠中观察到了应激诱导的对机械刺激的伤害感受反应的显著变化。慢性心理应激仅在高度焦虑的大鼠中显著增强膀胱伤害感受反应,这进一步支持了遗传、应激和焦虑作为诸如间质性膀胱炎(IC)等疼痛性泌尿生殖系统疾病的加重因素所起的关键作用。