Ljung T, Hellström P M
Department of Medicine, Karolinska Hospital, Karolinska Institutet, Stockholm, Sweden.
Acta Physiol Scand. 1999 Feb;165(2):225-31. doi: 10.1046/j.1365-201x.1999.00497.x.
The involvement of nitric oxide (NO) in the biological response to vasoactive intestinal peptide (VIP) on the migrating myoelectric complex (MMC) of small bowel and systemic arterial blood pressure was investigated in the rat. Animals were supplied with bipolar electrodes for electromyography of the small intestine and blood pressure was assessed by a pressure transducer connected to a carotid artery. In the first session, Nomega-nitro-L-arginine (L-NNA) was administered intravenously at 1, 2, 4 and 20 mg kg(-1). Effects of L-NNA at 1 and 20 mg kg(-1) were also studied after L-arginine 300 mg kg(-1). In the second session, intravenous infusion of VIP 500 pmol kg(-1) min(-1) was administered before and after L-NNA at 1 and 20 mg kg(-1). L-NNA at increasing doses stimulated myoelectric spiking of the small bowel until at 4 mg kg(-1) the MMC was disrupted and irregular spiking induced. Neither at 1 nor 20 mg kg(-1) did L-NNA affect the inhibitory motility response or decrease of blood pressure induced by VIP at a dose of 500 pmol kg(-1) min(-1). Our results show that effects of VIP on motility of the small intestine and systemic arterial blood pressure are direct and not dependent on NO as a common final link.
在大鼠中研究了一氧化氮（NO）参与血管活性肠肽（VIP）对小肠移行性肌电复合波（MMC）和全身动脉血压的生物学反应。给动物植入用于小肠肌电图的双极电极，并通过连接到颈动脉的压力传感器评估血压。在第一阶段，静脉注射Nω-硝基-L-精氨酸（L-NNA），剂量分别为1、2、4和20mg·kg⁻¹。在给予300mg·kg⁻¹的L-精氨酸后，还研究了1和20mg·kg⁻¹的L-NNA的作用。在第二阶段，在给予1和20mg·kg⁻¹的L-NNA之前和之后，静脉输注500pmol·kg⁻¹·min⁻¹的VIP。剂量递增的L-NNA刺激小肠肌电尖峰，直至4mg·kg⁻¹时MMC被破坏并诱导不规则尖峰。1和20mg·kg⁻¹的L-NNA均未影响500pmol·kg⁻¹·min⁻¹剂量的VIP诱导的抑制性运动反应或血压降低。我们的结果表明，VIP对小肠运动和全身动脉血压的作用是直接的，并不依赖于NO作为共同的最终环节。
