ABSTRACT
Background Formaldehyde and benzene homologues are common environmental pollutants, and their neurotoxicity has aroused widespread concern. Objective To investigate the effect of taurine on cognitive impairment after exposure to formaldehyde and benzene analogues in young rats. Methods Twenty four-week old SD rats were randomly divided into four groups, with six rats in each group: control group (clean air), model group (5 mg·m−3 formaldehyde + 5 mg·m−3 benzene + 10 mg·m−3 toluene + 10 mg·m−3 xylene), low-dose taurine intervention group (5 g·L−1 taurine + mixture of formaldehyde and benzene analogues), and high-dose taurine intervention group (10 g·L−1 taurine + formaldehyde and mixture of benzene analogues), and the exposure was administered by oral and nasal aerosol inhalation for 28 d. At the end of exposure, the learning and memory ability of rats in each group was measured by Morris water maze test. After the behavioral test, the rats were anesthetized and neutralized, and the brain tissue was harvested for histopathological and molecular biological tests. The apoptosis rate of neurons in hippocampal CA1 area was detected by Tunel assay, and the expression levels of apoptosis-related proteins such as caspase 3, bax, and bcl-2 in hippocampal tissue were detected by Western blotting. Results The growth and development of rats in each group were good during inhalation. During the Morris water maze experiment, the escape latencies of rats in the taurine intervention groups were not different from that in the control group (P>0.05) from day 3 to day 5 of training, while the escape latency of rats in the model group was significantly higher than that in the control group (P <0.05). The number of crossing platform and the target quadrant residence time in the high-dose taurine intervention group were not different from those in the control group (P>0.05), while the two variables in the model group and low-dose taurine intervention group were significantly lower than those in the control group (P <0.05). The apoptotic rates of neurons in the hippocampal CA1 area of rats in the control group, model group, and low-dose and high-dose taurine intervention groups were 5.11%, 18.87%, 9.39%, and 4.63%, respectively. The apoptotic rate in the model group was higher than those in the control group and low-dose and high-dose taurine intervention groups (P<0.05). The expression levels of caspase 3, bax, and bcl-2 in the hippocampus of rats in the low-dose and high-dose taurine intervention groups showed no difference compared with the control group (P>0.05). The expression levels of caspase 3 and bax in the model group were higher than those in the control group and low-dose or high-dose taurine intervention groups (P<0.05), and the expression levels of bcl-2 was lower (P<0.05). Conclusion The mixed exposure to formaldehyde and benzene analogues can damage the learning and memory ability of young rats, and increase the apoptosis of neurons in hippocampal CA1 region. Taurine can reverse the damage induced by formaldehyde and benzene analogues.
ABSTRACT
Objective@#To investigate the effects of simulated-thermobaric explosive gas on the respiration and nervous system in rats.@*Methods@#70 of SPF SD rats were randomly divided into four thermobaric explosive gas groups, two restoration observation groups and control group from April to August in 2018. The exposure time of in four thermobaric explosive gas groups were 3.75, 7.5, 15.0 and 30 min, respectively. The restoration observation groups were designed to observe for 30 and 120 min after exposure thermobaric explosive gas 30 min. The bloods were collected and analyzed at the end of exposure and recovery observation. The endogenous carbon monoxide (CO) , nitric oxide (NO) , glutamic acid (GLU) , acetylcholinesterase (AchE) and dopamine (DA) were detected in brain tissues, respectively.@*Results@#The blood gas index (pH, PCO2, PO2, COHb, O2Hb, MeHbt) and blood electrolytes (Na+, K+, Ca2+ and Cl-) in exposure groups have significant differences with these in control (P<0.05) . The pH value decreased with the exposure time longer. However, it basically returned to normal level when terminating exposure for 120 min. The concentration of PCO2, MeHb and CoHb increased first and then decreased with the exposure time extension. Conversely, The PO2 and O2Hb decreased first and then increased with the exposure time longer. The concentration of endogenous CO, GLU, and AchE decreased and NO increased in exposure group 4 and the restoration observation group 1 compared with those in control (P<0.01) . In addition, there were pathological changes in lung and brain tissue of exposure group, such as inflammatory cell infiltration and edema.@*Conclusion@#The blood gas index, electrolytes, neurotransmitter, histopathology of lung and brain were changed to various degrees by thermobaric bomb gas exposure. These findings would provide some beneficial support for evaluating the damage effect of thermobaric bomb gas on organisms.
ABSTRACT
OBJECTIVE: To explore the sub-chronic oral toxicity of 1,1-diamino-2,2-dinitroethene( FOX-7) in rats.METHODS: Ninety-six specific pathogen free healthy adult SD rats were randomly divided into control group,low-,medium-,and high-dose groups. Each group consisted of 24 rats,half of them were males and the other half were females.The low-,medium-,and high-dose groups of rats were exposed to 10,30,90 mg /( kg·d) body weigh of 1,1-diamino-2,2-dinitroethene by gavage for 90 days,once a day,6 days a week. The control group was given the same volume of 4%water starch solution. The toxic symptoms,the body weight,food utilization,routine blood,blood biochemical indicators,organ coefficients and histopathology changes of the rats were observed or tested. RESULTS: a) The body weights of male and female rats in the high-dose group in the 28 th day after exposure were lower than those of the control group for the same time and same sex( P < 0. 05). Food utilization in the male and female high-dose group in the 77 th and 90 th day after exposure were lower than those of the control group for the same time and same sex( P < 0. 05). b) Red blood cell counts,hemoglobin levels,hematocrit levels in the female rats of low-,medium-,and high-dose groups were lower than those of the female control group( P < 0. 05). Platelet counts in the female high-dose group was lower than that of the female control group( P < 0. 05). Red blood cell counts,hemoglobin level,hematocrit level and mean corpuscular hemoglobin concentration in the male high-dose group were lower than those of the male control group( P < 0. 05). The platelet counts in the male medium-,and high-dose group were lower than that of the male control group( P < 0. 05). c) Total cholesterol levels in female medium-,and high-dose group and blood urea nitrogen level in the female high-dose group were higher than those of the female control group( P < 0. 05). In high-dose group,the levels of total protein and uric acid were higher and lactate dehydrogenase level was lower than those of the control group( P < 0. 05). d) The spleen organ coefficients in the female high-dose group were higher and those in male medium- and high-dose groups were higher than those of the control group for same sex( P < 0. 05). The organ coefficients of liver and kidney in high-dose group were higher than those of the control group( P < 0. 05),the organ coefficients of testis and epididym in the male high-dose group were lower than those of the male control group( P < 0. 05). The testis convoluted tubule shrink and seminiferous cells decreased in the male high-dose group. e) The no observed adverse effect level of FOX-7 dinitroethene in female rats were less than10. 00 mg /( kg·d) and it was 10. 00 mg /( kg·d) in the male rats. CONCLUSION: FOX-7 could inhibit the growth of rats and damage the blood system and male reproductive system.