Protective effect of stellate ganglion block on delayed cerebral vasospasm in an experimental rat model of subarachnoid hemorrhage

• Published in: Brain research 2014-10, Vol.1585, p.63-71
• Main Authors: Hu, Na, Wu, Yun, Chen, Bai-Zhao, Han, Jin-Feng, Zhou, Mai-Tao
• Format: Article
• Language: English
• Subjects: Animals; Autonomic Nerve Block; Basilar Artery - pathology; bcl-2-Associated X Protein - metabolism; Biological and medical sciences; Blood and lymphatic vessels; Calcitonin Gene-Related Peptide - blood; Cardiology. Vascular system; Cerebral vasospasm; Disease Models, Animal; Diseases of the peripheral vessels. Diseases of the vena cava. Miscellaneous; Endothelin-1 - blood; Experimental subarachnoid hemorrhage; Hippocampus - metabolism; Male; Medical sciences; Middle Cerebral Artery - pathology; Neurology; Proto-Oncogene Proteins c-bcl-2 - metabolism; Rat; Rats; Rats, Sprague-Dawley; Stellate Ganglion - surgery; Stellate ganglion block; Subarachnoid Hemorrhage - complications; Vascular diseases and vascular malformations of the nervous system; Vasodilation; Vasospasm, Intracranial - metabolism; Vasospasm, Intracranial - prevention & control
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/j.brainres.2014.08.012

Abstract Stellate ganglion block (SGB) is a blockade of sympathetic ganglia innervating the head and neck, and is known to function through vasodilation of the target region. However, the effectiveness of SGB in relieving cerebral vasospasm (CVS) through dilation of intracerebral vessels has not been evaluated. The aim of the present study is to investigate the therapeutic effects of SGB in a rat model of subarachnoid hemorrhage (SAH) complicated by delayed CVS, and explore the underlying mechanisms. The SAH model was established by double injection of autologous arterial blood into the cisterna magna. We simulated SGB by transection of the cervical sympathetic trunk (TCST), and measured changes in the diameter, perimeter and cross-sectional area of the basilar artery (BA) and middle cerebral artery (MCA) to evaluate its vasodilatory effect. To investigate the underlying mechanisms, we determined the expression level of vasoactive molecules endothelin-1 (ET-1) and calcitonin gene-related peptide (CGRP) in the plasma, and apoptotic modulators Bcl-2 and Bax in the hippocampus. We found a significant increase in the diameter, perimeter and cross-sectional area of the BA and right MCA in SAH rats subjected to TCST. Application of SGB significantly reduced the expression of ET-1 while increasing that of CGRP in SAH rats. We also found a significant increase in the expression of Bcl-2 and decrease in the expression of Bax in the hippocampus of SAH rats subjected to TCST, when compared to untreated SAH rats. The mechanism of action of SGB is likely mediated through alterations in the ratio of ET-1 and CGRP, and Bax and Bcl-2. These results suggest that SGB can alleviate the severity of delayed CVS by inducing dilation of intracerebral blood vessels, and promoting anti-apoptotic signaling. Our findings provide evidence supporting the use of SGB as an effective and well-tolerated approach to the treatment of CVS in various clinical settings.