| Ischemic stroke is a main disease which compromises human's life and health. Over years its pathogenesis and prevention measures have been the foci of domestic and abroad medical research. Ischemic stroke is caused by a sudden shutdown of the local vessels in the brain and cessation of blood circulation. The neurons in the affected region are deprived oxygen and other nutrients they need for metabolism, resulting in severe ischemic neuronal death in the central region and ischemic penumbra form surrounding the infarcted brain tissue. All these constitute the infarction focus.The treatment to this disease is mainly focused on two areas. First, supply the treatment as soon as possible to improve the blood supply to the ischemic region; second, protect the ischemic brain tissue from further damage by metabolic toxins. The basic treatment is to recirculate the obstructed vessels before the irreversible hurt happens. Supply blood to the brain tissue lack of oxygen can save the brain function of the penumbra.As stellate ganglion (SG) is located in a unique position, dominates wide-scope tissue, has active physiological functions, stellate ganglion block (SGB) results in ideal treatment effects, more and more attention has been allured from clinicians and researchers in recent years. According to clinical observation, the treatment of ischemic stroke by SGB is effective, the earlier the better. But the basic theoretical research is rarely carried out either in China or abroad. SGB is to inject the local anesthetics to the loose connective tissue with SG of neck, thus sympathetic nerves controlling head, face, neck and upper limbs and other parts were blocked. SGB can increase blood flow to the dominated region, improve the circulation state and regulate the central nervous system, immune system and endocrine system.The rat has a similar cerebral vascular anatomy with the human. The models induced by middle cerebral artery occlusion (MCAO) are widely used as model of focal cerebral ischemia and simulate human ischemic stroke. Furthermore, rat with the transected cervical sympathetic trunk (TCST) also is an ideal animal model of continued SGB to human.TTC is recognized as the most reliable and sensitive method to show the injury of brain nerve cells. Calcitonin gene-related peptide (CGRP) can produce strong vasodilator effect and thus provides protection to brain. Endothelin (ET) is a vasoconstrictor neuropeptide released by endotheliocytes and neurons, whose synthesis and utilization are increased sharply by transient cerebral ischemia, which results in cerebral vessels to contract and spasm further and a serie of pathological reactions.All activities of a viable organism are performed by proteins finally, in other word it is proteins that carry out all the pathological and physiological functions. Proteome is defined as all kinds of proteins expressed by a cell in a certain physiological or pathological status. The technique and result of proteome are called proteomics which means the study of whole characteristic of proteins expressed by an intact organism or cell at a specific time and circumstances, which is used to obtain an overall cognition about physiological, pathological process of an organism at protein level.Modified Zea Longa`s method was used to establish the focal cerebral ischemic model with MCAO (M groups) and then TCST was adopted as a treatment (T groups). 6h, 24 h, 48 h and 72h after operations, survival rate of rats, cerebral infarction focus, the levels of CGRP and ET in serum were meatured respectively and the proteomics of the hippocampus between the groups after 48 h treatment were compared with 2-dimentional difference gel electrophoresis and mass spectrometry. This study is to approach the protective mechanisms of the TCST to rat suffering from focal cerebral ischemia, to provide the theoretical foundation for SGB to be widely used in clinical treatment of ischemic stroke and improve the survival rate and reduce mortality and further to establish foundations for drugs target design.The survival rates of the rats with TCST treatment at each time spot are higher than those without treatment (p<0.05). The areas of cerebral infarction focus in rats of T groups at each time spot from 6 to 72 hours were smaller than those of M groups (p<0.05). But the areas of cerebral infarction focus were fixed after 24 hours, and there were no significant differences between 48 hours and 72 hours (p>0.05). The contents of plasma CGRP in rats of T groups at each time spot was all higher than those of M groups (p<0.05). The contents of plasma ET in rats of M groups at each time spot was lower than those of M groups (p<0.05). Among the rat hippocampus from sham operated (S groups), M groups and T groups, totally 82 protein spots were found differentially expressed. Between the S groups and M groups, there were 69 differentially expressed proteins, of which 43 were increased and 26 decreased. Nine of them were identified. The contents of spectrin alpha chain, brain, heat shock protein 70, succinate dehydrogenase complex, subunit A Fp, glial fibrillary acidic protein delta, uracil DNA glycosylase were increased by MCAO, which were mainly related with heat shock protein, cytoskeleton, energy metabolism and injury repair. The contents of serine/threonine-protein phosphatase 2B catalytic subunit alpha isoform, serine/threonine-protein phosphatase PP1-beta catalytic subunit, diynamin-like protein DLP1 isoform DLP1-37, N-ethylmaleimide sensitive fusion protein were decreased which were mainly related with cell signalling, cytoskeleton and membrane fusion. Between the M groups and T groups, there were 13 differentially expressed proteins, of which 6 were increased and 7 decreased. Three of them were identified. The content of N-ethylmaleimide sensitive fusion protein was increased following TCST treatment which was related with membrane fusion. The contents of crystallin, mu, which was a heat shock protein and NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 10, mitochondrial precursor which was related with energy metabolism were decreased. Among them, N-ethylmaleimide sensitive fusion protein was worth special attention, whose content was increased after MCAO and decreased after TCST. This protein may be involved in the pathogenetic mechanism of cerebral ischemia and the protection by TCST.It can be concluded that in the rat of focal cerebral ischemia TCST can increase the plasma CGRP, decrease the plasma ET, improve the blood supply to the ischmic region, suppress the necrosis of neuron, minish the infarction focus, elevate the survival rate, decrease morbidity and provide some kind of protective effects on the brain. Thus the deduction can be got that TCST minished the infarction focus and elevated the survival rate in whole or at lease in part through CGRP and ET.On the basis of this model, the mechanism of the protection that TCST provided was revealed for the first time and some key different-expressed proteins with therapy meaning were identified. All these provided a support and powerful theoretical evidences for SGB to be widely used in clinical treatment of ischemic stroke and provide the candidates of target for the exploration of new drug for ischemic stroke. |
PDF Full Text Request