Effect of ulinastatin on cognitive dysfunction induced by isoflurane exposure in aged mice ã€Abstract】 Objective To evaluate the effect of pre-administration of ulinastatin on cognitive dysfunction in aged mice exposed to isoflurane. Methods Thirty-six healthy male SPF C57BL/6 mice, 18 months old, weighing 27-35 g, were randomly divided into 3 groups (n = 12); blank control group (C group), different Fluoroether group (group I), ulinastatin pre-administration group (group S). Groups I and S were exposed to 1% isoflurane for 3 h for 7 days; Group S was intraperitoneally injected with ulinastatin 50 000 U/kg 30 min before isoflurane exposure. Cognitive function tests were performed 24 h after the end of the last exposure, including Morris water maze and open field test. The mice were sacrificed immediately after the test, and the hippocampus were sacrificed. The interleukin-6 (IL-6) and interleukin were determined by ELISA. - 1β (IL-1β) and tumor necrosis factor-α (TNF-α) content. Results Compared with group C, the escape latency of group I was prolonged, the residence time of the original platform and the number of crossing platforms were reduced, the residence time of the central area of ​​the open field was shortened, and the contents of IL-1β and TNF-α in the hippocampus were increased (P < 0.05). There was no significant difference in the above indicators between the groups (P > 0.05). Compared with group I, the escape latency of group S was significantly shortened, the residence time of the original platform and the number of crossing the original platform increased, the residence time of the central area of ​​the market increased, and the contents of IL-1β and TNF-α in the hippocampus decreased (P < 0.05). Conclusion Pre-administration of ulinastatin can improve cognitive dysfunction in aged mice exposed to isoflurane, and its mechanism may be related to the inhibition of excessive release of inflammatory factors in hippocampus. ã€Key words】 Isoflurane; Ulinastatin; Old rats; Cognitive impairment; Hippocampus; Inflammation Postoperative cognitive impairment (POCD) is one of the common complications in elderly patients. Studies have shown that isoflurane can cause POCD. Therefore, it is of great significance to explore effective measures to prevent and treat cognitive dysfunction caused by isoflurane. Ulinastatin is a broad-spectrum protease inhibitor isolated from human urine that reduces excessive release of inflammatory mediators. Studies have shown that ulinastatin has neuroprotective effects, but its ability to effectively prevent cognitive dysfunction caused by isoflurane is not clear. This study was designed to evaluate the effect of pre-administration of ulinastatin on cognitive dysfunction induced by isoflurane exposure. 1 Materials and methods 1. 1 Experimental animals Healthy male SPF C57BL /6 mice 36, 18 months old, male, weighing 27 ~ 35 g, provided by the Experimental Animal Center of Sun Yat-sen University, indoor temperature 22 ° C, humidity 50%, 12 h / 12 h Keeping in the environment of alternating darkness and darkness. The random number table method was used to divide them into 3 groups (n = 12); blank control group (group C), isoflurane group (group I), and ulinastatin pre-administration group (group S). 1. 2 Methods According to the method of [4] and improved, the mice were placed in a closed anesthesia box, and a small hole in the top cover was connected with the catheter of the gas monitor to continuously monitor the concentrations of isoflurane, CO2 and O2 in the tank. The bottom of the anesthesia box was immersed in a constant temperature water bath at 37 °C. Group I and Group S were exposed to 1% isoflurane (batch number: 936245U, Abbott, USA) for 3 h, isoflurane was delivered as air (21% oxygen mixed with 79% nitrogen), fresh gas flow 1. 5 L/min For 7 consecutive days; group C inhaled air for 3 h; group S received intraperitoneal injection of ulinastatin 50 000 U/kg 30 min before isoflurane exposure. 1. 3 Morris water maze test and open field test (provided by Shanghai Xinsoft Information Technology Co., Ltd.) Morris water maze test and open field test were carried out 24 h after the end of the last exposure. In the navigational navigation experiment, the swimming speed and latency of the mice were recorded. The space exploration test was performed after the completion of the fourth day of the navigation test. At this point the platform is removed from the first quadrant. The mouse was placed in the quadrant of the quadrant from the quadrant of the positioning navigation platform, and stopped after swimming for 60 s each time. Record the number of target quadrant crossings and the target quadrant dwell time. The open field test lasted for 3 days. Timed from the time the mice were placed in the central grid, recording 15 min each time. Record the central area dwell time, the surrounding area dwell time, the total distance and the average rate. 1. 4 Interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) levels were determined immediately after the completion of cognitive function tests, and the bilateral hippocampus were stripped. Tissues were stored in an -80 ° C refrigerator and the contents of IL-6, IL-1β and TNF-α in hippocampus were determined by ELISA. Weigh the hippocampus, dilute to 400 μL, follow the kit instructions, according to the concentration of the standard and the corresponding absorbance (OD450 value) by Curve Expert1. 3 Software analysis A standard curve is prepared. The samples are obtained according to the microplate reader. The contents of the hippocampal IL-6, IL-1β and TNF-α are calculated using the equation of the standard curve. 1. 5 Statistical methods SPSS 16. 0 statistical software was used, and the t-test was used for comparison between measurement data groups. 3 Discussion Exploring the causes of perioperative POCD and avoiding and preventing POCD have become an urgent problem to be solved. 18-month-old C5 /7 mice are equivalent to human middle-aged age. Therefore, 18-month-old mice were selected as the study subjects in order to understand the damage of isoflurane on learning and memory in aged rats. According to the RAMMES study, the mouse isoflurane MAC value was (1.33 ± 0.16)%, so this study used a 1% isoflurane concentration for 3 h anesthesia exposure protocol. The Morris water maze is an experimental method applied to the study of brain learning and memory mechanisms. It is very common in learning and memory, new drug development, hippocampus/external hippocampus research, pharmacology, and toxicology. The open field test is a classical experimental model for evaluating animal behavior, which mainly reflects the autonomous behavior and inquiry behavior of animals in the new environment. The results of Morris water maze and open field test in this study suggest that the learning and memory ability and spatial exploration ability of group I are lower than those of the control group, while the difference between group S and group C is not statistically significant, indicating ulinastatin. It can alleviate the damage of learning and memory ability in aged mice exposed to isoflurane. The results of this study suggest that pre-administration of ulinastatin may improve cognitive dysfunction in aged mice exposed to isoflurane, and its mechanism may be related to the reduction of excessive release of hippocampal inflammatory factors. The release of neuronal inflammatory factors (IL-1β, TNF-α, IL-6, etc.) can lead to cognitive decline. The release of inflammatory factors can inhibit the long-term potentiation of hippocampus, and long-term hippocampal enhancement is the key to learning and memory in hippocampus. In addition, IL-1β activates Caspase-3, which leads to neuronal apoptosis and impairs cognitive function through the IL-1β/Caspase-3/neuronal pathway. Ulinastatin regulates systemic inflammatory response, inhibits the release of pro-inflammatory cytokines, and promotes the release of anti-inflammatory cytokines. Ulinastatin is a broad-spectrum protease inhibitor isolated from human urine and is effective in inhibiting the activity of various proteases, glycosidases, and lipolytic enzymes. In sepsis, shock and ischemia-reperfusion injury of heart, lung, liver and intestine, ulinastatin has obvious effects of inhibiting the release of inflammatory factors and protecting the organ function. Studies have shown that ulinastatin can reduce cerebral ischemia-reperfusion injury in in vitro and in vivo experiments in a model of cerebral ischemia-reperfusion. Another study confirmed that ulinastatin inhibits the release of inflammatory cytokines such as IL-1β and TNF-α in a neuropathic pain model, antagonizing chronic neuropathic pain caused by inflammatory factors. The results of this study showed that compared with the control group, the levels of IL-1β and TNF-α in the hippocampus of group I were elevated, suggesting that isoflurane anesthesia can promote the inflammatory response of hippocampus in aged mice, resulting in decreased cognitive function. The mechanism may be related to the increase in intracellular calcium concentration caused by isoflurane, activation of the NF-κB signal transduction pathway, and promotion of inflammatory responses. The concentration of pro-inflammatory cytokines IL-1β and TNF-α in the pre-administration group of ulinastatin was significantly reduced, which could significantly reduce the neurocognitive impairment associated with the neuroinflammatory reaction. Fish Bone Molding 18G100mm,Fish Bone Molding 18G100mm Bolt,Fish Bone Molding 18G100mm Filter,Fish Bone Molding 18G100mm In Inches Qingdao Beautiful Skin Biotechnology Co., Ltd , https://www.hafilleresthetic.com
