Carbohydrazide CAS NO. 497-18-7
Carbohydrazide can act as an oxygen scavenger to prevent corrosion, especially in boiler feedwater systems, rocket propellant assemblies, color image and soap stabilizers, antioxidant rubber, boiler water deoxidizers and metal passivators. Carbohydrazide can also be used as an anticorrosive agent. Organic synthesis of intermediates.
CAS No. 497-18-7 EINECS 207-837-2
Molecular Formula CH6N4O Molecular Weight 90.08
Attributes:
Carbohydrazide is a white crystalline powder or granule. The effective content of carbohydrazide is from 98.0 to 100.0%.
Specifications:
Items
Index
Appearance
White crystal line powder or pellets
Active Content (%)
98.0-100.9%
PH (12% Solution, @ 25 ℃)
8.45±1.25
Free Hydrazine
≤250ppm
Chloride (Cl)
≤10ppm
Sulfate (SO4)
≤20ppm
Silica (SiO2)
≤10ppm
Copper (Cu)
≤1ppm
Iron (Fe)
≤4ppm
Sodium (Na)
≤4ppm
Lead (Pb)
≤4ppm
Moisture
≤0.2%
Packaging and storage:
Pack 25 kg or 50 kg with woven bags or fiber drums.
Store in a cool, dry, well-ventilated area away from incompatible materials. Please close the container when not in use.
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OBJECTIVE: To investigate α7nACh receptor competitive antagonist (MLA) learning and memory abilities of mice in the Morris water maze.
Key words : competitive antagonist of α7nACh receptor; Morris water maze; learning and memory ability; mouse
Effect of competitive antagonists of α7nACh receptor on learning and memory ability of experimental mice
Effect of α 7nACh receptor competitive antagonist on learning and memory ability mice
Methods Male Kunming mice were intraperitoneally injected with MLA (110, 418 μg/g) for 8 days. The Morris water maze was used to observe the learning and memory ability of mice by positioning navigation and space exploration experiments. Results The intraperitoneal injection of MLA 418μg/g was significantly longer than that of the other three groups ( P < 0101), and the percentage of swimming time in the target quadrant was also significantly decreased ( P < 0101). Conclusion MLA 418μg/intraperitoneal injection. The mice of g have a decline in learning and memory.
A competitive antagonist of the α7nACh receptor is methylphylcaconitine (MLA), an extract of the genus Delphinium spp1, which is a phytotoxin [1 - 2 ]. Recent animal studies have shown that MLA leads to cognitive dysfunction in animals through competitive antagonism of the α7 nACh receptor [3–4]. In this study, the Morris water maze was used to detect the learning and memory ability of mice. The dementia model simulating α7nACh receptor damage was proposed to further study the α7nACh receptor in degenerative nervous system such as Alzheimer's disease. The mechanism of action of the disease and the experimental basis for the development of drugs for the treatment of α7nACh receptor damage.
1 Materials and methods
111 Experimental animals and groups were selected from healthy male 3-month-old Kunming mice (purchased from Experimental Animal Center of Ningxia Medical College). 85 randomly selected 35 were used to determine the maximum escape latency experiment, and the remaining 50 were before the official start of the experiment. One day, the mice were free to swim for 2 min in the Morris water maze, and 40 mice with the same swimming posture and speed were selected and randomly divided into 4 groups, 10 in each group. 1) Normal control group: mice were free to eat drinking water, natural circadian rhythm lighting; 2) saline group: injection of the same amount of normal saline; 3) 110μg / g group: daily injection of MLA 110μg / g, for 8d; 4) 418μg / Group g: MLA 418 μg/g was injected daily for 8 days.
112 Reagents and Instruments MLA: Powder, purchased from Sigma. Morris water maze and microcomputer bio-function system, purchased from Chengdu Taimeng Technology Co., Ltd.
113 MLA solution preparation and dosage before application 110μg / g and 418μg / g MLA were dissolved in physiological saline, respectively, according to 011mL / 10g
The dose was continuously injected for 8 days.
114 Morris water maze behavior determination water maze is a circular pool, the pool wall is milky white, the wall is marked with four water inlet points of east, south, west and north, and the pool is divided into four quadrants: SW, MW, SE and NE. Place a circular transparent platform in the center of the SW quadrant. The top of the platform is 1cm below the water surface and the water temperature is (26 ±1) °C. Add enough milk to the water to avoid seeing the underwater platform. The maze is hanging on the camera and connected to a computer and other recording and display systems. During the experiment, the environment is kept quiet, and the reference objects (such as doors, windows, refrigerators, and electric lights) remain unchanged.
11411 Determination of the maximum escape latency: 35 mice were selected, and the water maze training was performed in two sessions in the afternoon and in the afternoon. The training was performed 4 times in each period. The mice were free to swim for 2 minutes during the training. After adapting to the environment, the mice were oriented to the pool. The wall is placed in the water and the maximum time limit from the point of entry to the platform is recorded. During the training, the operator randomly selects a water inlet point, but in the same training period, each mouse has the same water inlet point. The platform could not be found within 120s, and the mice were guided to the platform for 10s, for 2 consecutive days, and the time to find the platform was recorded. After the experiment,
The time to find the platform was determined by more than 90% of the mice, and the maximum escape latency was determined.
11412 Injection MLA Animal Positioning Navigation: The mice screened and grouped were trained for 5 days from the first day, and the latency and swimming speed were recorded. The arithmetic mean of the 3d was statistically analyzed. After the injection of MLA, the training was continued in the same way for 8 days, and the arithmetic mean of 8d was taken for statistical analysis.
11413 Injecting MLA animal spatial test test: After training 5d and 8 days after MLA injection, the underwater platform was removed, and the midpoint of the platform quadrant was the entry point. The search platform of the mouse within 120s was recorded in each quadrant. Swimming time.
115 statistical methods
All data were expressed as ( . x ± s) using Oneway ANOVA. When the variance is homogeneous, LSD (Le Significant Difference) or Student Newman Keuls test is used for pairwise comparison. When the variance is not uniform, the rank is used. And test, compare Kruskal Wallisttest between groups. Statistical analysis was performed on the data using SPSS 1110 statistical software.
2 results
211 Maximum latency measurement results Of the 35 mice, 2 were rotated in situ.
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Journal of Ningxia Medical College
Journal of Ningxia Medical College
Vol. 28 3
　 June 2006
Not excluded from the experimental requirements. Thirty-one of the 33 mice were trained 2d (16 times) and were able to find the platform within 70s after the 16th training.
90% of the time, therefore, the maximum incubation period is determined to be 70s.
212 injection MLA animal positioning navigation test
21211 escape latency: After 5 days of training, there was no significant difference in escape latency between the groups and the normal control group ( P > 0105); after MLA injection,
The escape latency of the 418μg/g group was significantly longer than that of the normal control group ( P < 0101). There was no significant difference in the escape latency between the other groups and the normal control group ( P > 0105), as shown in Table 1.
21212 Swimming speed: After 5 days of training and after injection of MLA, there was no statistically significant difference between the experimental group and the normal control group ( P > 0105), suggesting that the exercise capacity of the mice after injection of normal saline and MLA was not affected (Table 1). .
Table 1 Group of mice positioning navigation test to find the average latency and average speed of the hidden platform
Group latency (s) swimming speed (cm/s)
Training 5d injection MLA 8d training 5d injection MLA 8d
Normal control 33.03 ±1.61 18.46 ±1.41 12.42 ±1.92 11.05 ±1.19
Saline 32.68 ±4.99 17.11 ±1.45 11.12 ±1.29 11.84 ±4.03
MLA 110μg/g 31.54 ±4.99 15.11 ±1.46 13.09 ±3.21 10.56 ±1.59
MLA 418μg / g 29.65 ± 5.34 47.95 ± 9.313 11.21 ± 1.35 10.13 ± 0.59
Comparison with the incubation period of the control group 3 P < 0101
213 Injecting MLA animal space search test training until the 5th day, there was no statistically significant percentage of the quadrants of the platform in the normal control group ( P > 0105); after the MLA injection, the 418 μg / g group and the normal control group platform quadrant residence time The percentage comparison was statistically significant ( P < 0101), and the other groups were not statistically significant compared with the normal control group ( P > 0105), as shown in Table 2.
Table 2 Space exploration experiments of each group of mice in the target
The percentage of time in the quadrant
Group platform quadrant dwell time percentage (%)
Training 5d injection MLA 8d
Normal control 45.12 47.61
Saline 49.52 45.33
MLA 110μg / g 41.87 45.62
MLA 418μg / g 41.23 29.98*
Compared with the control group * P < 0101
3 discussion
With the deepening of the research on the learning and memory brain mechanism and the need to find effective methods to prevent and treat cognitive disorders, objective and accurate evaluation of the learning and memory levels of experimental animals has become a very important research content in neurobiology and neuropharmacology. The Morris water maze was designed by the British psychologist Morris in the early 1980s and is mainly used in the study of the neurobiological mechanisms of learning and memory and the study of neuropharmacology (including pharmacology of traditional Chinese medicine) [5]. However, Morris used this maze test method to target rats. After reviewing the data, it was also applied to mice, but the training methods were different [6 - 8 ]. In our test, the training was 5 d, divided into two periods, the last two sessions, each training 4 times, the experiment is basically stable until the third day, suggesting that the Morris water maze is also suitable for the memory behavior test of mice. The test of 35 mice, the maximum latency was determined to be 70s, which is more suitable in this experiment, which excludes the difference in memory ability of mice due to different training time, and also saves time and ensures the completion of the experiment. However, due to the large workload of the training, the small number of staff, and the small sample size tested, further research is needed to more accurately determine the appropriate range of the maximum latency of the mouse. The experimental data of Morris water maze is more complicated, and its statistical analysis is also more difficult. Especially, how to carry out statistical analysis of the escape latency measured by the mouse during positioning navigation has many problems. In this experiment, according to the normal control group, the escape latency gradually decreased after 5d training period and 8d test period, but basically stabilized after 2d training. Therefore, the average escape latency of the last 3d was taken as the average training. The incubation period was statistically analyzed. The a7nACh receptor is absent in the early stages of Alzheimer's disease (AD) and is considered to be an early symptom of AD. Therefore, attempts have been made to investigate the relationship between structure, distribution and function of AD with the a7nACh receptor. However, due to the small difference between the neuronal nicotinic receptor (nAChR) subtypes and the large number, the α7nACh receptor subtypes are not only species-specific, but also change with age. Therefore, it is necessary to find α7nACh. Receptor subtype-specific antagonists or agonists are very difficult, although in recent years some progress has been made in the synthesis of competitively specific agonists [9], but antagonists with high affinity and high specificity are still rare. Currently, only a-bungarotoxin [10] and a-conotoxinI2mI and methyllycaconitine (MLA) [11]. MLA has a higher affinity for mammalian neuronal a7nACh receptors than other nicotinic receptors. After intraperitoneal injection of MLA 110 and 418 μg/g in this experiment, it was found that MLA was impaired in mouse memory in a dose-dependent manner, suggesting that a suitable dose of MLA could be established to simulate a target damage of the a7nACh receptor. Animal models provide a basis for further study of the mechanism of action of α7nACh receptors in neurodegenerative diseases such as AD and the development of drugs for the treatment of α7nACh receptor damage.