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Objective: To explore the protective effect of glutamine (GLN) on the hyperoxia-induced lung injury of the neonatal rats through endoplasmic reticulum stress (ERS) pathway, and to elucidate its mechanisms. Methods: A total of 90 Wistar rats were randomly divided into control group (FiO2 =21%), hyperoxia group (FiO2 85%), and hyperoxia+GLN group (Fi2 85%, the concentration of intraperitoneal injection of GLN was 0. 75 g · kg-1 · d-1); there were 30 rats in each group The body weights and water contents in the lung tissue of the neonatal rats were measured on the 3rd, 7th and 14th days of the experiment. HE staining was used to determine the morphology of lung tissue of the rats. The superoxide dismutase (SOD) activity in lung tissue of the rats was detected by nitro blue tetrazolium chloride (NBT), and the malondialdehyde (MDA) level was determined by thiobarbital acid (TBA). The expression levels of Caspase-12, GADD153, GRP78, Bel-2, and Bax in lung tissue of the rats were detected by Western blotting method. Results: Compared with control group at the same time, the body weights of the neonatal rats in hyperoxia group on the 3rd, 7th and 14th days were significantly decreased (P<0. 05), the water contents in lung tissue of the neonatal rats were increased (P<0. 05), the SOD activities were significantly decreased (P<0. 05), the levels of MDA in the lung tissue of the neonatal rats were increased (P<0. 05), the expressions levels of Caspase-12, GADD153, GRP78 and Bax proteins were significantly increased (P<0. 05), and the expression levels of Bcl-2 protein and the Bcl-2/Bax ratios were significantly decreased (P<0. 05). Compared with hyperoxia group at the same time, the body weights of the neonatal rats in hyperoxia + GLN group on the 3rd, 7th and 14th days were significantly increased (P<0. 05), the water contents in lung tissue of the neonatal rats were decreased (P<0. 05), the SOD activities were significantly increased (P< 0. 05), the levels of MDA in lung tissue of the neonatal rats were decreased (P<0. 05), the expression levels of Caspase-12, GADD153, GRP78 and Bax proteins were significantly decreased (P<0. 05), the expression levels of Bcl-2 protein and the Bcl-2/Bax ratios were increased (P<0. 05). The pathological sections of lung tissue of the rats in control group showed that lung tissue structure was regular, no alveolar edema was found, the alveolar size and alveolar septum were approximately the same, and no inflammatory cell infiltration was found; the histopathological sections of lung tissue of the rats in hyperoxia group showed swelling of brochial and alveolar epithelial cells, enlargement of alveolar lumen, edema of interstitial cells, inflammatory cell infiltration and fibrous exudation; the degrees of alveolar damage, the inflammatory exudation and the proliferation of fibrons tissue in hyperoxia+GLN group were alleviated which was between hyperoxia group and control group. Conclusion: GLN can alleviate the hyperoxia-induced lung tissue edema and inflammatory response of the neonatal rats, and one of mechanisms is that GLN can down-regulate the expression levels of Caspase-12, GADD153, GRP78 and Bax proteins and up-regulate the expression level of Bcl-2 protein through ERS pathway to protect hypoxic lung injury.
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Objective: To explore the protective effect of glutamine (GLN) on the hyperoxia lung injury in the neonatal rats, and to elucidate its mechanism. Methods: A total of 90 male and female Wistar rats were selected and randomly divided into control group (FiO2: = 21%). hyperoxia group ( FiO2: > 85%) and hyperioxia + glutamine (GLN) group (FiO2: > 85%) (n=30). The rats in hyperioxia group and hyperioxia + GLN groups were used to establish the models of hyperoxia lung injury (HALI). The rats in hyperoxia+ GLN group were intraperitoneally injected with 0. 75 g • kg-1 • d-1 GLN from the first day of experiment, and the rats in other two groups were abdominally injected with the same volume of normal saline. The body weights, water contents in the lung tissue of the neonatal rats in various groups on the 3rd. 7th. and 14th days of the experiment were measured. I IF staining was used to determine the morphology of lung tissue of the rats in various groups; ELISA was used to detect the levels of interleukin-6 (IL-6)∗ interleukin-1|ß (IL-lf3) and tumor necrosis factor-a (TNF-a) in the lung tissue homogenate of the rats in various groups. Results: Compared with control group at the same time, the weights of the neonatal rats in hyperoxia group were significantly decreased on the 3rd. 7th and 14th days ( P∗CO. 05); the body weights of neonatal rats in hyperoxia + GLN group were significantly higher than those in hyperoxia group at the same time (P<0. 05). On the 3rd. 7th. and 14th days, the water contents of lung tissue of the rats in hyperoxia group were higher than those in control group at the same time ( P< 0. 05). and the difference was gradually increased with the prolongation of time; the water contents of lung tissue of the rats in hyperoxia • GLN group were significantly lower than those in hyperoxia group ( P
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OBJECTIVE: To compare the different effect of electroacupuncture (EA) at "Zusanli" (ST36) and "Chize" (LU5) of mother rats exposed to Nicotine during pregnancy and lactation on lung function and morphological changes in offspring rats, so as to explore the most effective acupoint for improving the development of lung in neonatal rats. METHODS: A total of 24 female pregnancy SD rats were randomly divided into 4 groups: normal control, model, EA-ST36 and EA-LU5 (n＝6 rats in each group). Rats of the normal group were treated by subcutaneous injection of normal saline, and those of the other 3 groups treated by subcutaneous injection of nicotine (1 mg•kg－1•d－1) beginning from the 6th day to about the 21st day of pregnancy (childbirth day) for nicotine exposure during pregnancy and lactation. The daily EA treatment (2 Hz /15 Hz，1 mA) was applied to bilateral ST36 and LU5 for 20 min, beginning from the 6th day of pregnancy to the 21st day (childbirth day). The lung function of the offspring rats including the peak inspiratory flow (PIF), peak expiratory flow (PEF), lung resistance (RL), exhalation resistance (RE)and lung dynamic compliance (Cdyn) was detected by using a lung function analysis system. Histopathological changes (severity of alveolarization) of the offspring rats' lung tissue were observed under microscope after H．E. stain. RESULTS: Compared with the normal group, the PIF, RL and RE values were significantly increased (P0.05)．. CONCLUSION: EA of ST36 and LU5 of mother rats experiencing nicotine exposure during pregnancy and lactation can improve the lung function and morphological changes in neonatal rats, and the effect of ST36 is relatively better.
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Objective To observe the effects of 3 neuroprotective measures on the expressions of apoptosis-related factors and their ligands (Fas and FasL) in brain tissue of neonatal rats with hypoxic ischemic brain injury. Methods One hundred and twenty Wistar rats 7 days old were selected as experimental subjects, the rats were divided into four groups: neural stem cell, erythropoietin (EPO), ω-3 unsaturated fatty acid treatment groups and hypoxic ischemic brain damage model group according to random number table method, with 30 rats in each group. Neural stem cell group, EPO group and ω-3 unsaturated fatty acid group were respectively injected with neural stem cells, EPO and ω-3 unsaturated fatty acid, each 5 mL via tail vein after modeling; the hypoxic ischemic brain damage model group was given equal volume of normal saline. At 6, 12, 24, 48 and 72 hours after administration of drug, 6 rats were sacrificed in each group, brain tissue was taken, the mRNA expression levels of Fas/FasL, protein expression levels of Toll-like receptor 4 (TLR4), nuclear transcription factor-κB (NF-κB), tumor necrosis factor-α (TNF-α), interleukin (IL-1β, IL-6) and cell apoptotic rate in hippocampus tissue were measured. Results ① mRNA expressions: the mRNA expressions of Fas and FasL of the 3 experimental groups were significantly lower than those of the hypoxic ischemic brain damage model group, the degrees of descent after administration for 24 hours were the most significant, neural stem cell treatment group < EPO treatment group < ω-3 unsaturated fatty acid treatment group < hypoxic ischemic brain damage model group [Fas mRNA expression (2-ΔΔCt): 140.5±2.9, 156.4±2.5, 165.2±2.7 vs. 173.7±2.8, FasL mRNA expression (2-ΔΔCt): 143.1±4.3, 154.6±1.5, 160.7±1.4 vs. 174.7±2.8], the differences were statistically significant (all P < 0.05). ② Protein expressions: the protein expressions of TLR4, NF-κB, TNF-α, IL-1β, IL-6 of the 3 experimental groups were significantly lower than those of the hypoxic ischemic brain damage model group (TLR4/GAPDH: 0.7±0.2, 0.6±0.1, 0.2±0.1 vs. 1.4±0.1; NF-κB/GAPDH: 6.7±0.4, 5.3±0.1, 1.1±0.2 vs. 11.2±0.3; TNF-α/GAPDH: 14.3±1.4, 11.2±1.2, 3.2±2.1 vs. 23.2±0.5; IL-1β/GAPDH: 9.4±0.2, 7.4±0.3, 2.2±0.3 vs. 13.4±0.1; IL-6/GAPDH: 36.2±4.4, 39.3±1.5, 26.2±2.1 vs. 51.4±1.4, all P < 0.05), the protein expression levels of above indexes in neural stem cell treatment group < those of EPO treatment group < those of ω-3 unsaturated fatty acid treatment group < those of hypoxic ischemic brain damage model group. ③ Apoptotic rates:after drug administration, the apoptotic rates of the ω-3 unsaturated fatty acid group, EPO treatment group, neural stem cell treatment group were obviously lower than the rate of model group [(3.7±0.3)%, (3.4±0.2)%, (2.5±0.1)% vs. (5.5±0.4)%, all P < 0.05]. Conclusion The mRNA expressions of Fas/FasL in the brain of neonatal rats with hypoxic-ischemic brain damage are high, and the treatment with each of the following agents; neural stem cells, EPO and ω-3 unsaturated fatty acid can reduce the mRNA expressions of Fas/FasL in such rats' brain tissues.
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Objective To investigate the effect of estradiol on sevoflurane-induced epileptiform cor-tical EEG waves in neonatal rats. Methods Forty neonatal rats,aged 4-6 days,weighting 8-15 g,were di-vided into 5 groups according to random number table:normal saline control group (group C),estradiol group (group E),ICI182780 (group I),Formestane group (group O) and estradiol +ICI182780 (group EI). Af-ter establishing the monitoring model of cortical electroencephalogram in neonatal rats, EEG was recorded continuously for 30 minutes, then different treatment drugs were given according to different groups. After 30 minutes of continuous recording of EEG, anesthesia induction was started with inhalation of 6% sevoflurane for 3 minutes, followed by inhalation of 2. 1% sevoflurane to maintain anesthesia. Sevoflurane anesthesia las-ted for 1 hour. The righting reflex disappearance time was recorded after sevoflurane anesthesia. The total du-ration,single duration and frequency of EEG convulsion waves were recorded. Spike frequencies were recor-ded at different periods. Animal respiratory rate was recorded after sevoflurane induction. Results One rat in group I and one rat in group EI showed convulsion wave before treatment,which were excluded from the study. The righting reflex disappearance time of group S,group E,group I,group O and group EI were (24. 4 ±2. 5)s,(16. 4±4. 2)s,(31. 8±5. 2) s,(29. 8±1. 8) s,(24. 8±2. 7) s respectively,and there were statisti-cally significant differences among the 5 groups (F=16. 693,P<0. 01). There were no significant difference in respiratory frequency among the 5 groups (F=0. 276,P>0. 05). Compared with group S,the total dura-tion,single duration and frequency of convulsion wave were significantly increased in group E during anesthe-sia,and the differences were statistically significant (P<0. 05). Compared with group E and group S,the total duration,single duration and frequency of convulsion wave during anesthesia were significantly reduced in group I,group O and group EI,and the differences were statistically significant (P<0. 05). Compared with group S,the spike frequency of group E increased significantly in each period,and the differences were statis-tically significant (P<0. 05). The frequency of spike wave in group I,group O and group EI at 65-70 min and 90-95 min were lower than that in group S,and the differences were statistically significant (P<0. 05). The frequency of spike wave between group O and group EI during 115-120 min was statistically different with group S and group E(P<0. 05). Conclusion The mechanism of epileptiform EEG wave induced by sevoflu-rane anesthesia may be related with neuroactive steroidal estradiol.
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Objective To investigate the effects of cyclinA2 and its inhibitor p21 on alveolar development in bronchopulmonary dysplasia (BPD) neonatal rats.Methods Eighty newborn rats were randomly divided into a model group (FiO2 =80％-85％) and a control group (FiO2 =21％).The degree of alveolar development was evaluated by radial alveolar count (RAC) and alveolar septal thickness.The distribution and expression of cyclinA2 and p21 were detected by immunohistochemistry and Western blot.Results The RAC value of the model group was lower than that of the control group from 3 days.The thickness of the alveolar seprum was higher than that of the control group from 7 days (P ＜0.05).The expression of p21 protein in the model group began to increase from 3d,peaked on 14d,and lasted for 21d.The expression of cyclinA2 protein in model group was higher than that in control group at 14d and 21d (P ＜0.05).There was a negative correlation between RAC and p21 protein expression in model group (r =-0.5966,P ＜0.01),and no correlation with cyclinA2 (r=0.7276,P＞0.05);there was no correlation between RAC and p21 in the control group (r =-0.2929,P ＞ 0.05),and positively correlated with cyclinA2 (r =0.8476,P ＜ 0.01).The alveolar septal thickness of the model group and the control group were both positively correlated with p 21 (r =0.4291,P＜0.05;r=0.4447,P ＜0.05),and negatively correlated with cyclinA2 (r=-0.6814,P ＜0.01;r=-0.7636,P ＜0.01).Conclusion The imbalance of cell cycle regulatory protein cyclinA2 and its inhibitor p21 expression in neonatal rats exposed to hyperoxia may be one of the related factors that interfere with the development of BPD alveoli.
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Aim To study the effects of daidzein on sodium channel current ( /Na) in ventricular myocytes of rats and the mechanism of its antiarrhythmia. Methods The effect of daidzein on the viability of ventricular myocytes was delected by MTT assay; single ventricular myocytes from rats were isolated by single enzymatic hydrolysis; the changes of /N, and its dynamic characteristics in rat ventricular myocytes before and after administration of daidzein were observed, recorded and analyzed by cell patch clamp technique. Results MTT experiments showed that the ICjo of daidzein was 30 to 100 jjimol • L"1 ,so the concentration of 0. 3 - 10 jimol • L"1 was chosen for the subsequent experiments. When daidzein was given 0. 3,1,3,10 pjnol • L"',the /Nb amplitude of ventricular myocytes in rats showed a concentration-dependent inhibition. The concentration of daidzein 0. 3 imol • L"1 also had certain effect on the time course of /Nt. The /Nl, peak decreased gradually over time. The 1,3,10 jimol • L"1 daidzein raised the I-U curve obviously. Under the same condition, the activation curve moved to the direction of depolarization. The steady-state inactivation curve shifted toward hyperpolarization, and the t value of the recovery curve was prolonged after inactivated state. Conclusions Daidzein significantly inhibited the Na∗ channel of ventricular myocardium in rats, which may l)e one of its mechanisms of anti-arrhythmia.
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Abstract Aim Obesity during pregnancy is one of the most established risk factors for negative long-term programming. The aim of the present study was to investigate the effects of maternal consumption of a high-fat diet during pregnancy and lactation on the weight gain, visceral adipose tissue and cholesterolemia in neonatal rats. Methods Wistar rats were divided into two groups according to the mother's diet during pregnancy and lactation: Control group (CG, n = 12) were the offspring of rats fed a standard diet (4% lipid) and the Test group (TG, n = 12) were pups rats fed on a high fat diet (23% lipid). The weight of the animals was measured on alternate days until the 22nd day of life, when collected visceral adipose tissue and blood were collected for biochemical analysis. For statistical analysis the Student t test, Sidak´s teste and two way ANOVA was used, with p <0.05. Results the test group showed differences in weight gain, visceral adipose tissue and higher cholesterol. Conclusion a maternal exposure to a high-fat diet during pregnancy and lactation can promote changes in weight gain, hypercholesterolemia and an increase in adipose tissue in neonatal rats.
Resumo Objetivo A obesidade durante a gestação é um dos fatores de risco mais estabelecidos para uma programação negativa em longo prazo. O objetivo do presente estudo foi investigar os efeitos do consumo materno de uma dieta hiperlipídica durante a gestação e lactação no aumento do peso, do tecido adiposo visceral e colesterolemia em ratos neonatos. Métodos Ratos Wistar foram divididos em dois grupos de acordo com a dieta da mãe durante a gestação e lactação: grupo controle (GC, n=12) composto por filhotes de ratas alimentadas com uma dieta padrão (lipídios 4%) e o grupo teste (GT, n=12) composto de filhotes de ratas alimentadas com dieta hiperlipídica (lipídios 23%). O peso dos animais foi aferido em dias alternados até o 22° dia de vida, quando foi coletado sangue para análises bioquímicas. Para a análise estatística utilizou-se os seguintes testes: two way ANOVA, teste de Sidak e teste t de Student, com p< 0,05. Resultados O grupo teste mostrou diferença no ganho de peso, no tecido adiposo visceral e nos níveis de colesterol. Conclusão Uma exposição materna a uma dieta hiperlipídica durante a gestação e lactação pode promover maior ganho ponderal, hipercolesterolemia e um aumento do tecido adiposo em ratos neonatos.
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Animals , Female , Pregnancy , Rats , Prenatal Exposure Delayed Effects/metabolism , Lactation/physiology , Adipose Tissue/pathology , Cholesterol/blood , Diet, High-Fat/adverse effects , Animals, Newborn/metabolism , Prenatal Exposure Delayed Effects/physiopathology , Pregnancy, Animal/physiology , Rats, Wistar , Disease Models, Animal , Lipids/blood , Animals, Newborn/growth & development , Obesity/pathologyABSTRACT
Objective To investigate the effect of hypothermia on the learning and memory a-bility of neonatal rats during anesthesia and its possible mechanism.Methods Forty SD rats aged 7 d were randomly divided into 4 groups (n=10):control group (group C),anesthesia group (group A),anesthesia and hypothermia group (group AH),hypothermia group (group H).Group C was in-jected intraperitoneally with 0.1 ml of saline and equipped with heating pad to keep the rectal temper-ature at 38-39℃.Group A was injected with propofol 0.1 ml at 25 mg/kg intraperitoneally with 1/2 of the initial dose,and anesthesia was maintained for 2 h.The same method to maintain the rectal temperature at 38-39℃;Group AH of anesthesia and time and Group A of the same,rats in the anes-thesia process is not insulation,control room temperature of 23℃,allowing the body temperature de-creased;Group H rats intraperitoneal injection of 0.1 ml saline,the same control room temperature of 23℃,so that the natural temperature drop.Anesthesia in the process of continuous oxygen,inter-mittent monitoring of body temperature.Immediately after awake,5 rats in each group were randomly selected to detect the content of p-ERK and p-CREB in hippocampus by Western blot.The spatial learning and memory ability and p-ERK and p-CREB contents in hippocampus were measured by water maze test.Results The rectal temperature in group AH and group H decreased to (25.38± 0.22)℃ and (25.54±0.20)℃ in 1 h respectively,and the body temperature decreased significantly compared with group C(38.36±0.24)℃ and group A(37.40±0.29)℃ (P<0.05).Compared with group C and group A,the expression of group AH and group H was decreased (P<0.05).At the end of the water maze test,the expression of protein in the four groups was not statistically signifi-cant.There was no significant difference between the four groups in the escape latency,the number of crossing the platform and the quadrant of the original platform quadrant.Conclusion The expression of p-ERK and p-CREB in neonatal rats hippocampus can be short-term inhibition in the period of hy-pothermia at 25℃,but no significant effect on the long-term learning and memory ability.
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Objective To explore the long-term effects of dexmedetomidine on the brain development in propofol-induced neonatal rats.Methods Thirty-five seven-day-old Sprague-Dawley rats of both genders,weighing 10-15 g,were randomly divided into seven groups (n =5) using a random number table:normal saline group (group N),intralipid group (group F),propofol 100 mg/kg group (group P),dexmedetomidine 75 μg/kg (group D),dexmedetomidine 25 μg/kg,50 μg/kg and 75μg/kg+propofol 100 mg/kg groups (groups PD25,PD50 and PD75),neonatal rats in each group were treated according to the corresponding dosing regimen.After fully awake,the rats were allowed to mature until postnatal week 9 and the spatial learning and memory capacities were tested by Morris water maze.The rats were sacrificed after the tests.Brain was sliced for determination of hippocampal apoptosis by TUNEL assays and the expression of postsynaptic density protein 95 (PSD95) by immunohistochemistry.Results Compared with group N,the escape latency was significantly prolonged,the times of platform crossing were significantly decreased,the hippocampal apoptosis ratio was significantly increased and the expression of PSD95 was significantly down-regulated in groups P,PD25 and PD50 (P＜0.05).Compared with group P,the escape latency was significantly shortened,the times of platform crossing were significantly increased and the hippocampal apoptosis were significantly decreased in groups PD50 and PD75 (P＜0.05),the expression of PSD95 was up-regulated in group PD75 (P＜0.05).Compared with group PD25,the escape latency was significantly shortened,the number of platform crossing was significantly increased and the hippocampal apoptosis were significantly decreased in groups PD50 and PD75 (P＜0.05),the expression of PSD95 was significantly up-regulated in group PD75 (P＜0.05).Compared with group PD50,the hippocampal apoptosis were significantly decreased,the expression of PSD95 was significantly up-regulated in group PD75 (P＜ 0.05).Conclusion The addition of dexmedetomidine 50,75 μg/kg attenuates propofol-induced neurocognitive impairment in neonatal rats after aducthood,partially by attenuating hippocampal apoptosis and upregulating the expression of PSD95.Dexmedetomidine alone was not neurotoxic to the developing brain.
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Objectives To explore the effect of exogenous erythropoietin (EPO) on the expression of glial fibrillary acidic protein (GFAP) in hippocampal CA1 region and 5- bromide -2- uracil (BrdU) in hippocampal DG region in neonatal Wistar rats with hypoxic-ischemic brain damage (HIBD). Methods Forty-eight Wistar rats aged 7 days were randomly divided into HIBD model group and EPO experimental group, and another 24 rats as sham operated group. The HIBD model was established by ligating the right common carotid artery and inhaling hypoxia gas mixture (8％ O2 and 92％ N2) for 2 h. The expression of GFAP in hippocampal CA1 region and the number of BrdU positive cells in the hippocampus were detected by immunohistochemical method on at 14 d, 21 d, and 28 d after operation and compared among three groups. Results On 14 d and 21 d after operation, the expression of GFAP in CA1 region and the number of BrdU positive cells were statistically different among three groups (P<0.01) with EPO experimental group having the highest, HIBD model group having the second highest and sham operation group having the lowest in both, . On 28 d after operation, there was no difference in the expression of GFAP and the number of BrdU positive cells in the DG among three groups (P>0.05). At different time point (14 d, 21 d, 28 d) in every group, the expression of GFAP in CA1 region and the number of BrdU positive cells in DG region were all statistically different (P<0.01), all with the highest on 14 d after operation, second highest on 21 d, and the lowest on 28 d. Conclusions Early administration of exogenous EPO can promote the expression of GFAP in hippocampal CA1 region and increase the number of BrdU positive cells in DG region, which indicates that EPO can promote the proliferation and regeneration of damaged neurons. EPO had neuroprotective effect on neonatal rats with hypoxic-ischemic brain damage.
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Abstract Aim Obesity during pregnancy is one of the most established risk factors for negative long-term programming. The aim of the present study was to investigate the effects of maternal consumption of a high-fat diet during pregnancy and lactation on the weight gain, visceral adipose tissue and cholesterolemia in neonatal rats. Methods Wistar rats were divided into two groups according to the mother's diet during pregnancy and lactation: Control group (CG, n = 12) were the offspring of rats fed a standard diet (4% lipid) and the Test group (TG, n = 12) were pups rats fed on a high fat diet (23% lipid). The weight of the animals was measured on alternate days until the 22nd day of life, when collected visceral adipose tissue and blood were collected for biochemical analysis. For statistical analysis the Student t test, Sidak´s teste and two way ANOVA was used, with p 0.05. Results the test group showed differences in weight gain, visceral adipose tissue and higher cholesterol. Conclusion a maternal exposure to a high-fat diet during pregnancy and lactation can promote changes in weight gain, hypercholesterolemia and an increase in adipose tissue in neonatal rats.
Resumo Objetivo A obesidade durante a gestação é um dos fatores de risco mais estabelecidos para uma programação negativa em longo prazo. O objetivo do presente estudo foi investigar os efeitos do consumo materno de uma dieta hiperlipídica durante a gestação e lactação no aumento do peso, do tecido adiposo visceral e colesterolemia em ratos neonatos. Métodos Ratos Wistar foram divididos em dois grupos de acordo com a dieta da mãe durante a gestação e lactação: grupo controle (GC, n=12) composto por filhotes de ratas alimentadas com uma dieta padrão (lipídios 4%) e o grupo teste (GT, n=12) composto de filhotes de ratas alimentadas com dieta hiperlipídica (lipídios 23%). O peso dos animais foi aferido em dias alternados até o 22° dia de vida, quando foi coletado sangue para análises bioquímicas. Para a análise estatística utilizou-se os seguintes testes: two way ANOVA, teste de Sidak e teste t de Student, com p 0,05. Resultados O grupo teste mostrou diferença no ganho de peso, no tecido adiposo visceral e nos níveis de colesterol. Conclusão Uma exposição materna a uma dieta hiperlipídica durante a gestação e lactação pode promover maior ganho ponderal, hipercolesterolemia e um aumento do tecido adiposo em ratos neonatos.
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Objective To evaluate the effects of penehyclidine hydrochloride on the oxidative stress and cell apoptosis during endotoxin-induced acute lung injury (ALI) in neonatal rats.Methods Forty 7-day-old Wistar rats weighing 12-18 g were randomly divided into 3 groups (n=10 each) using a random number table: penehyclidine hydrochloride group (group PHC), acute lung injury (group AKI) and normal saline group (group NS).The ALI model was induced with intraperitoneal endotoxin 5.0 mg/kg in groups PHC and ALI.In group PHC, penehyclidine hydrochloride 2.0 mg/kg was injected intraperitoneally at 1 h before ALI respectively, while the equal volume of normal saline was administered in groups NS and ALI.At 4 h after endotoxin injection,the rsts were sacrificed.The lungs were collected to determine the wet/dry (W/D) lung weight ratio.The expression of SOD was detected by xanthine oxidase method.The expression of MDA was detected by sulfuretted barbitone method.Levels of cytochrome C (Cyt-C) and Caspase-3 were determined with immunohistochemical method (IHC), and cell apoptosis (by TUNEL).Apoptotic index was calculated.Results Compared with group NS, the W/D ratio and the contents of MDA were significantly increased, the contents of SOD were significantly decreased in groups ALI and PHC (P＜0.05).Compared with group ALI, the W/D ratio and the contents of MDA were significantly decreased, the contents of SOD were significantly increased in group PHC (P＜0.05).Compared with group NS, the contents of Cyt-C, Caspase-3, and apoptotic index were significantly increased in groups ALI and PHC (P＜0.05).Compared with group ALI, the contents of Cyt-C, Caspase-3, and apoptotic index were significantly decreased in group PHC (P＜0.05).Conclusion Penehyclidine hydrochloride ameliorates endotoxin-induced ALI by inhibiting oxidative stress and cell apoptosis in neonatal rats.
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Aim To study the effects of propofol on apoptosis of cortical astrocytes isolated from neonatal rats.Methods Pure astrocytes(AST)were obtained from the cultured cerebral cortical cells and identified by the GFAP stain technology in neonatal rats.AST cells were treated with different concentrations of propofol(0,10,30,90 μmol·L-1)for 8 hours.Cell viability was measured by MTT method,and the apoptosis was detected by Annexin V/PI double staining.Cytochrome C(cyt-C)leakage was detected by Western blot.Caspase-3 and caspase-9 activities were measured by spectrophotometry.Results AST cells were administered with different concentrations of propofol(0,10,30,90 μmol·L-1)for 8 hours.It decreased the survival rate in a concentration-dependent manner,induced the leakage of cyt-C in mitochondria,up-regulated the expression of pro-apoptotic protein caspase-3 and caspase-9,and induced AST apoptosis.Conclusion Propofol induces the apoptosis of astrocytes in neonatal rat cortex in vitro,which may be related to the activation of mitochondria apoptosis pathway induced by mitochondrial cyt-C release.
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Aim To investigate the effect of Trillium tschonoskii Maxim ( TTM ) ethanol extract on hypoxia ischemia brain damage ( HIBD ) in neonatal rats and potential mechanisms. Methods Fifty healthy SD rats of 7 day-old were randomly divided into three groups:the sham operation group ( n=10 ) , the model group ( n=20 ) and TTM treatment group ( n=20 ) , which received 3-day intraperitoneal injection of normal saline or ethanol extract of TTM respectively. TTC staining and Nissl staining were performed to detect the cerebral ischemia area and neuronal death. Western blot was used to detect the expression of Bcl-2 and Bax. Re-sults The brain tissue of model group was slightly swollen, and white necrotic zone induced by ischemia occured on the right side of the brain, while the brain morphology of TTM treatment group was good. After TTC staining, ischemia zone was clearly seen on the right side of the brain in model group, while after TTM treatment, the size of ischemic zone was decreased. Compared with the model group , Nissl staining showed the neuronal cells increased in TTM treatment group. Western blot showed the expression of Bcl-2 protein in TTM group increased than that in HIBD model group ( P <0. 01 ) , while the expression of Bax protein de-creased ( P <0. 01 ) . Conclusion TTM therapy is beneficial for HIBD,which may be related to reducing neuronal apoptosis.
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Objective To investigate the expression of nuclear factor-kappa Bp65 (NF-κBp65)and Toll-like receptor 4(TLR4)protein in the brain tissues of 7-day-old Sprague-Dawley(SD) rats with cerebral hypoxia-ischemia encephalopathy (HIE) and to explore the role of TLR4 and NF-κBp65 in the pathogenesis of neonatal rats with hypoxic-ischemic brain damage.Methods Seven-day SD rats were randomly divided into the experimental group and the control group.Brain pathological changes were observed in light microscopy at 6 h、12 h、24 h、72 h、7 d after HIE.The expression of TLR4 and NF-κBp65 in brain tissues were analyzed by immunohistochemistry method.Results NF-κBp65 and TLR4 were expressed in the neuron and microglia of control group and experimental group.The expression were most significant at cerebral cortex and hippocamp.However,the expression of NF-κBp65and TLR4 began to increase at HIE 6h:NF-κBp65 (0.219 3 ± 0.024 7,0.215 7 ±0.030 4)and TLR4(0.327 1 ±0.033 3,0.303 9 ±0.037 9),and achieved the hightest at HIE 24h:NF-κBp65 (0.3564±0.0235,0.3365 ±0.023 2)and TLR4(0.434 2 ±0.0428,0.4193 ±0.041 3),then decreased at HIE 72 h:NF-κBp65 (0.289 2 ± 0.032 0,0.260 9 ± 0.021 2) and TLR4 (0.300 5 ± 0.020 9,0.282 0 ± 0.022 6),and HIE 7 d:NF-κBp65(0.247 9 ±0.0340,0.242 1 ±0.025 4) and TLR4(0.274 4 ±0.0288,0.257 1 ±0.027 5).Conclusion There is a positive correlation between NF-κBp65 and TLR4 in rats with HIE.It suggested that they may have the same pathophysiology development in HIE.
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Objective To investigate the role of histone lysine methyltransferase G9a in sevoflurane-induced cognitive impairment in the developing brain of neonatal rats.Methods Thirty-six 5-day-old male SD rats were randomly divided into 3 groups (n =12):control group,sevoflurane group and Bix01294 (the inhibitor of histone lysine methyltransferase G9a)group.The rats in the sevoflurane group and the Bix01294 group received 3% sevoflurane anesthesia for 2 hours once a day at postnatal 5-7 days (P5-P7 ).The rats in the Bix01294 group received Bix01294 (10 mg/kg)subcu-taneously at 1 5 min before anesthesia,and the rats in the control group and sevoflurane group received normal saline for injection (0.1 ml)at the same time.The open-field test and fear condition-ing test were performed at P3 5 and P3 9-P41 ,respectively.The tissues of hippocampus were collected at P42 to measure the levels of G9a,histone H3 lysine 9 dimethylation (H3K9me 2 )and synapsin 1. Results Compared with the control group,the percentage of freezing time of sevoflurane group was significantly decreased in the contextual fear condition test,while the levels of G9a and H3K9me 2 were significantly increased and the level of synapsin 1 was significantly decreased (P <0.01).How-ever,the percentage of freezing time of Bix01294 group was significantly increased,while the levels of G9a and H3K9me 2 were significantly decreased and the level of synapsin 1 was significantly in-creased compared with the sevoflurane group (P <0.05).There was no difference in the total distance and residence time in the central grid in the open-field test,and the percentage of freezing time in the cued fear condition test among the three groups.Conclusion Histone lysine methyltransferase G9a is involved in the sevoflurane-induced long-term cognitive impairment in developing brain of neonatal rats,which may be associated with the increase of H3K9me 2 and the down-regulation of synapsin 1 in the hippocampus.
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Objective To investigate the effect of different concentrations of dexmedetomidine on the apoptosis of hippocampal neurons in neonatal rat induced by propofol in vitro. Methods Hippocampal neurons of primary cultured neonatal SD rat were divided randomly into three groups. Group C (control group)was normal cultured without any treatment for 12 h; group P (Propofol group)was incubated with 12 μg/mL propofol for 12 h and group DP (Dexmedetomidine + propofol group)was incubated with 0.002 5 ~ 25 μg/mL dexmedetomidine for 30 min, and then further incubated with 12 μg/mL propofol for 12 h. Results Compared with that of group C, the apoptosis rate of hippocampal neurons increased in group P and DP (P < 0.05 or P < 0.01); Compared with that of group P, the apoptosis rate of neurons decreased with the increase of dexmedetomidine concentration in group DP (P<0.05 or P<0.01). The result of transmission electron microscope indicated that compared with group C , group P showed obvious neuronal damage; the nerve cells damage alleviated in group DP, which were negatively associated with the concentration. Conclusions With the concentration ranging from 0.002 5 to 25 μg/mL, dexmedetomidine set pre-incubation and breeding can reduce apoptosis of hippocampus neuron of neonatal rats induced by propofol and the effect is concentration dependent.
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Objective To observe the effect of hippocampal DNA methyltransferases (DNMTs)on neonatal cognitive impairments induced by sevoflurance exposure.Methods Sixty-four 7-day old male Sprague-Dawley rats were randomly divided into the following four groups (n =1 6):control group (group C),sevoflurane group (group S),sevoflurane+NaCl group (group SN),and sevoflurane+5-AZA group (group SA).Sevoflurane animals received 3% sevoflurane plus 30% oxy-gen for 2 hours daily for 3 consecutive days,and rats in group C were placed into the same container, which contained 30% oxygen only.Animals in group SA were intracerebroventricularly injected with 5-AZA (1 mg/kg),while group SN same volume of NaCl one hour before sevoflurane exposure. Open field and Morris water maze were given the four weeks after anesthesia (n =8).Rats without any behavior tests from each group (n =8)were euthanized 4 weeks after the treatment and the hip-pocampus was harvested.Quantitative real-time PCR and Western blot were used to detect the mRNA and protein levels of DNMT1,DNMT3a and DNMT3b.Results In the open field test,no significant difference was observed in the distance travelled and the time spent in the center of the arena.Com-pared with the group C,group S showed an increase in the latency,decreased time spent in the target quadrant,and the mRNA and protein levels of DNMT3a and DNMT3b in the hippocampus were sig-nificantly increased (P < 0.05).Compared with the group SN,group SA showed a decrease in the la-tency,more time spent in the target quadrant,and the mRNA and protein levels of DNMT3a and DNMT3b in the hippocampus were decreased (P < 0.05).There was no significant difference in the expression of DNMT1 among the four groups.Conclusion Sevoflurane exposure induces neonatal cog-nitive impairments later in life,which was accompanied by the increased mRNA and protein levels of DNMT3a and DNMT3b in the hippocampus.By contrast,pretreatment of 5-AZA decreased hipp-ocampal DNMT3a and DNMT3b,and ameliorated cognitive impairments.These results suggest that DNMTs are involved in sevoflurane induced neonatal cognitive impairments.
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Hypoxia-ischemia (HI) is a major cause of brain damage in the newborn. Several studies elicited the neuroprotective effects of progesterone in adult rats but there is very little literature available on neonatal rats. Therefore the present study is undertaken to see the effect of progesterone in hypoxic ischemic brain injury in neonatal rats, using an established neonatal HI rat pup model. Seven-day-old rat pups were subjected to right common carotid artery ligation and then 60 minutes hypoxia. The first dose of progesterone to treatment group was administered by peritoneal injection (4 mg/kg), after 10 minutes of exposure and subsequent doses were given by subcutaneous injection at 6 h, 24 h and 48 h intervals. Control group was also exposed to HI and was given only the vehicle (peanut oil) through the same route and intervals as that of treatment group. After 96 h, the pups were perfused with 10% formalin and brains were sampled and stained with toluidine blue. Cells density and number of pyramidal cells of the hippocampal Cornu Ammonis (CA) regions were examined by stereological methods. The histomorphometric assessment of the effects of progesterone showed minimal but no significant protective value in the volume, cells density and total number of pyramidal cells of hippocampal CA region of the treatment and control groups (p>0.05) after HI. Our results concluded that 4 mg/kg of PROG had no significant neuroprotective effect in HI model of the neonatal rat's hippocampus.
La hipoxia-isquémica (HI) es una causa importante de daño cerebral en el recién nacido. Varios estudios indican los efectos neuroprotectores de la progesterona en ratas adultas, sin embargo existe poca literatura disponible en ratas recién nacidas. Por tanto, el presente estudio se llevó a cabo para ver el efecto de la progesterona en la lesión cerebral HI en ratas recién nacidas, utilizando un modelo de cría de rata neonata HI establecido. A los siete días de nacidas, las crías de ratas fueron sometidas a la ligadura de la arteria carótida común derecha y luego 60 minutos de hipoxia. La primera dosis de progesterona fue administrada al grupo de tratamiento mediante inyección peritoneal (4 mg/kg), después de 10 minutos de exposición y las dosis posteriores fueron administradas por inyecciones subcutáneas en intervalos de 6 h, 24 h y 48 h. El grupo control también fue expuesto a HI y se le administró solamente aceite de cacahuete a través de la misma ruta y con los intervalos que recibió el grupo de tratamiento. Después de 96 h, las crias fueron perfundidas con formalina al 10% y se tomaron muestras de los cerebros, los que se tiñeron con azul de toluidina. La densidad celular y el número de células piramidales de las regiones del hipocampo Cornu Ammonis (CA) fueron examinadas por métodos estereológicos. La evaluación histomorfométrica de los efectos de la progesterona mostró un valor protector mínimo, pero no significativo en el volumen, densidad de las células y el número total de células piramidales de la región de CA del hipocampo de los grupos de tratamiento y control (p>0,05) después de HI. En conclusión, nuestros resultados indican que 4 mg/kg de progesterona no tuvo efecto neuroprotector significativo en el modelo de HI del hipocampo de ratas neonatas.