Ryberg Anders T, Soukup Ondrej, Tobin Gunnar
Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, 405 30 Göteborg, Sweden.
Adv Pharmacol Sci. 2009;2009:787586. doi: 10.1155/2009/787586. Epub 2009 May 25.
In the in vivo experiments on anaesthetized sheep, it was presently examined whether muscarinic receptor antagonists with diverse selectivity affect the release of VIP in response to electrical stimulation of the parasympathetic chorda tympanic nerve differently, and if the changes in the release could be associated to altered secretory and vasodilator responses. The location of the muscarinic receptor subtypes was examined also. In the experiments, blood was collected out of the submandibular venous drainage before and during electrical stimulation of chorda tympani nerve in the absence and presence either of pirenzepine or methoctramine. While metchoctramine increased the output of protein, pirenzepine inhibited flow of saliva and increased protein output, vasodilatation, and VIP output. In morphological examinations, the inhibitory muscarinic M4 receptor occurred interacinarily in the gland. It is concluded that prejunctional muscarinic receptors, most likely of the M4 subtype, exert inhibitory modulation of the parasympathetic release of VIP in the ovine submandibular gland.
在对麻醉绵羊进行的体内实验中，目前研究了具有不同选择性的毒蕈碱受体拮抗剂是否会以不同方式影响副交感鼓索神经电刺激后血管活性肠肽（VIP）的释放，以及释放的变化是否与分泌和血管舒张反应的改变有关。还研究了毒蕈碱受体亚型的定位。在实验中，在鼓索神经电刺激之前和期间，在不存在和存在哌仑西平或甲溴东莨菪碱的情况下，从下颌下静脉引流中采集血液。虽然甲溴东莨菪碱增加了蛋白质的输出，但哌仑西平抑制了唾液分泌并增加了蛋白质输出、血管舒张和VIP输出。在形态学检查中，抑制性毒蕈碱M4受体存在于腺泡间。得出的结论是，节前毒蕈碱受体，很可能是M4亚型，对绵羊下颌下腺副交感神经释放VIP发挥抑制性调节作用。
