Effects of sport fatigue and poverty of movement on neuroendocrine system in Wistar rats

AIM: To observe the different changes of neuroendocrine systems between the state of sport fatigue and poverty of movement. METHODS: 60 male Wistar rats were randomly divided into three groups: normal control group, sport fatigue model group and poverty of movement model group (20 rats in each group). The sport fatigue model was established by the method of combining basal diet and loaded swimming during 2 weeks, whereas the method of restricted activities was used to establish the poverty of movement model with total experimental time of 10 weeks. By the end of experiment, the climbing pole time was determined. The contents of hypothalamus thyrotropin releasing hormone (TRH), and serum norepinephrine (NE) and epinephrine (E) in rats with different treatments were determined by ELISA. In addition, the changes of hypothalamus corticotropin release hormone (CRH), pituitary adrenocorticotropic hormone (ACTH) and thyroid stimulating hormone (TSH), and serum corticosterone (CORT), triiodothyronine (T3), tetraiodothyronine (T4) were determined by radioimmunoassay to evaluate the functions of adrenergic nerve-adrenomedullin system, hypothalamo-pituitary-adrenal (HPA) axis and hypothalamo-pituitary-thyroid (HPT) axis. RESULTS: Compared to control group, the climbing pole time of the animals was obviously decreased in two model group. The adrenergic nerve-adrenomedullin system and HPA axis were inhibited in sport fatigue model rats, but HPT axis was unchanged. Interestingly, the HPA axis was hyperfunctional and HPT axis was inhibited in poverty of movement model rats. However, no change in the adrenergic nerve-adrenomedullin system was observed. CONCLUSION: Sport fatigue and poverty of movement all affect neuroendocrine system and lead to the adjustment mechanism imbalance, but the target and tendency are different.     

Influence of vestibular training on plasma levels of stress-related hormones in rats with motion sickness

AIM: To investigate the relationship between motion sickness and the plasma levels of stress-related hormones in the rats before and after vestibular training.METHODS: Conditioned taste aversion (CTA) was induced in 72 female SD rats after rotatory stimulation. The magnitude of CTA was measured to reflect the susceptibility of rats to motion sickness. The plasma levels of corticosterone, adrenocorticotrophic hormone (ACTH), corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) were analyzed by radioimmunoassay. Hormone levels were determined before and after rotatory stimulation, and after 1 month of vestibular training when the rats obtained habituation to this rotation.RESULTS: CTA to 0.15% saccharin solution in rats after the rotatory stimulation was completely inhibited after vestibular training, suggesting that a habituation of the rats to motion sickness was obtained. The rotatory stimulation induced an elevation in the plasma levels of corticosterone, ACTH and AVP, and this response of corticosterone to rotation was greatly reduced after vestibular training. The plasma levels of all 4 hormones in the rats insusceptible to motion sickness were higher than those in susceptible group, especially the plasma levels of corticosterone and ACTH after rotation, and the basal level of CRH. In addition, after vestibular training, the basal plasma levels of corticosterone, ACTH and CRH in both groups were higher than those before training, and a slight elevation was also observed in the basal level of AVP.CONCLUSION: Vestibular training may induce a habituation to rotatory stimulation in rats, thus inhibiting the development of motion sickness. The difference of the susceptibility of rats to motion sickness may negatively relate to the basal plasma levels of stress-related hormones.     

Effects of voluntary wheel running exercise on depressive-like behavior and circadian rhythmic alterations of neuroendocrine induced by chronic unpredictable mild stress in rats

AIM: To investigate the effect of 8-week middle intensity voluntary wheeling exercise on the depressive-like behavior and the circadian rhythmic alterations of plasma hormone and peptide induced by chronic unpredictable mild stress (CUMS) in rats. METHODS: Male Sprague-Dawley rats (n=90) were randomly divided into model group, model+exercise group and control group. Rats in model+exercise group received 8-week voluntary wheel running exercise plus CUMS procedure during the last 3 weeks at the same time. Exploratory locomotor activity was assessed by open field test, the anxiety-like behavior was measured by elevated plus-maze test, and lack of pleasure was detected by sucrose preference test. Blood samples were collected at each of 6 time points (ZT1, 5, 9, 13, 17 and 21 on the 2nd day after behavior testing). Plasma concentrations of corticosterone (CORT), melatonin (MT) and vasoactive intestinal peptide (VIP) were detected by ELISA. The plasma concentration of adrenocorticotropic hormone (ACTH) was measured by radioimmunoassay. The circadian rhythm changes of serum CORT, MT, VIP and ACTH concentrations in each group were compared by cosinor analysis. RESULTS: Compared with control group, locomotor activity, weight gain and sucrose consumption in model group were significantly reduced (P<0.01). The values of the percentage of open-arm time (OT%) and open arm entries (OE%) were obviously lower in model group than those in control group (P<0.01). Eight-week voluntary wheel running exercise may improve the above depression behavior caused by CUMS. The rats in model group showed an obvious disorder in circadian rhythm of plasma ACTH and CORT, including phase advance and decrease in amplitude. There also showed a markedly blunted circadian rhythm and decreased level of plasma MT in model rats compared to control rats. VIP expression was significantly higher than that in control group with 24 h rhythm, but the amplitude was significantly lower than that in control group, peak phase also delayed for 6 h. Eight-week exercise significantly ameliorated the abnormal expression and the disturbance secretion rhythm of ACTH, CORT, MT and VIP in plasma. CONCLUSION: Eight-week voluntary wheeling exercise ameliorates CUMS-induced depressive-like behaviors probably by rescuing the disturbed circadian rhythms and abnormal secretion of these neuroendocrine factors.     

Activation of corticotrophin releasing hormone-containing neurons in hypothalamic paraventricular nucleus contributes to sympathoexcitation in rats with congestive heart failure

AIM:To observe the expression of corticotropin releasing hormone (CRH) within the paraventricular nucleus of hypothalamus (PVN) and to explore the relationship between the activated CRH-containing neurons and sympathetic activity in rats with heart failure (HF).METHODS:Healthy male Sprague-Dawley (SD) rats were subjected to coronary artery ligation to induce HF,and chronic intracerebroventricular (ICV) infusion was performed by osmotic pump for 4 weeks.The rats in sham group and HF group were given vehicle (VEH;artificial cerebrospinal fluid 0.25 μL/h).The rats in HF plus treatment group were treated with CRH competitive inhibitor αh-CRH (15 mg/h).Meanwhile,the Lewis rats and Fischer 344 rats for control study also underwent coronary ligation to induce HF or sham surgery.After 4 weeks,left ventricular end-diastolic pressure (LVEDP) and maximum positive/negative change in pressure over time (±dp/dt_max) were determined.The right ventricular-to-body weight (RV/BW) and lung-to-body weight (lung/BW) ratios were calculated.The renal sympathetic nerve activity (RSNA) was recorded and the plasma norepinephrine (NE) level was measured.The expression of CRH in the PVN combined with the plasma adrenocorticotrophic hormone (ACTH) levels were measured.RESULTS:Compared with the sham-SD rats,the HF-SD rats had a greater number of CRH positive neurons in the PVN (accordingly the plasma ACTH levels were increased),accompanied by decreased±dp/dt_max and increased RSNA,plasma NE,LVEDP,lung/BW and RV/BW.However,ICV treatment with αh-CRH attenuated these changes in the HF-SD rats (P<0.05).Compared with the sham-Fisher 344 rats,the HF-Fisher 344 rats also had a greater number of CRH positive neurons in the PVN (accordingly the plasma ACTH levels were increased).In addition,they had significantly increased RSNA and plasma NE level,higher LVEDP,RV/BW and lung/BW,and lower±dp/dt_max(P<0.05).Compared with the SHAM-Lewis rats,the HF-Lewis rats had not significantly changed in the above parameters.CONCLUSION:In CHF,the CRH-containing neurons in PVN are activated,thus aggravating cardiac function by increasing sympathoexcitation.     

Effect of ACTH on pain behavior and the level of brain-derived neurotrophic factor and corticotropin-releasing hormone in the hippocampus of rats with chronic pain

AIM: To observe the effect of adrenocorticotropic hormone(ACTH) on the levels of brain-derived neurotrophic factor(BDNF), trkB and corticotropin-releasing hormone(CRH) in the hippocampus of arthritic rats.METHODS: The BDNF immunoreactivity(IR) and CRH-positive neurons were stained with immunohistochemistry and in situ hybridization methods, respectively.RESULTS: The BDNF-IR, CRH mRNA-positive neurons in the contralateral hippocampus of the arthritic rats were increased significantly, which was decreased markedly by intraperitoneal injection of ACTH. However, the effect of ACTH was attenuated after adrenalectomy(ADX).CONCLUSION: These results suggest that BDNF and CRH in the hippocampus of arthritic rats were involved in the modulation of chronic pain, ACTH produced its analgesic effect by inhibiting the increase in BDNF and CRF level. Adrenal is critical to the analgesic action of ACTH.     

Bacterial cell wall components of Staphylococcus aureus induce endophthalmitis

AIM: To compare the responses of intraocular inflammation induced by heat-inactivated Staphylococcus aureus or its bacterial cell wall components in SD rats. METHODS: The rats were randomly divided into heat-inactivated bacteria (HIB) group (96 rats were injected with 10 μg of HIB), heat-inactivated bacteria fragments (HIBF) group (96 rats were injected with 10 μg of HIBF), peptidoglycan (PGN) group (96 rats were injected with 10 μg of PGN) and control group (96 rats were injected with sterile saline equivalent). At time points of 6 h, 12 h, 24 h, 48 h, 72 h and 5 d after vitreous injection of the pathogens, the ocular inflammation scores were determined under slit lamp microscope. The infiltration of white blood cells were counted in histological sections. The levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and cytokine induced neutrophil chemoattractant-1 (CINC-1) in serum and vitreous body were detected by ELISA, and protein concentration in aqueous humor were also measured. RESULTS: Severe ocular inflammation was observed in the animals of HIB, HIBF and PGN groups 6-72 h after injection. Five days after injection, the endophthalmitis subsided. The peak of intraocular white blood cell infiltration was observed 24 h after exposure to the bacteria and the components in each group and the cell infiltration rapidly declined after 3 days. The concentrations of TNF-α and IL-1β peaked at 24 h in each group, maintained to 48 h, then decreased rapidly, and returned to baseline level after 5 days. The concentration of CINC-1 peaked at 12 h in each group, and maintained to 24 h, then decreased rapidly, and returned to the normal level after 3 days. Significantly higher protein levels in aqueous humor were detected in the experimental groups at all time points as compared to that in control group (P<0.01). CONCLUSION: Staphylococcus aureus cells and its components induce typical experimental endophthalmitis in SD rats. Massive leukocyte infiltration and high levels of TNF-α, IL-1β and CINC-1 are the main pathological features in the experimental model. PGN and the bacterial cell wall fragments induce stronger intraocular inflammations than the whole heat-inactivated S. aureus.     

苹果miR396家族鉴定及在不定根发育过程中的表达分析

分析了苹果miR396家族进化特性及其在苹果不定根发育过程中的表达模式。结果表明:苹果miR396家族有4条成熟体和7条前体序列(pre-miRNA)。Mfold预测显示Pre-miR396家族7个成员序列均可形成典型稳定的茎环二级结构,最小折叠自由能介于–62.9 kal·mol^-1(pre-miR396b)～–51.9kal·mol^-1(pre-miR396g)之间。系统发育进化树分析显示,pre-miR396家族亲缘关系可分为3个亚组(G1、G2、G3),每个亚组内基因数量不同,分别含有11、9、19个。靶基因预测显示,苹果miR396靶基因包括MdGRF1、MdGRF2和MdGRF5等,降解组测序进一步验证了mi R396对其候选靶基因MdGRF1、MdGRF2和MdGRF5的剪切关系。苹果miR396家族成员在侧根和果实中的表达量显著高于其他组织,其候选靶基因表达量则在花芽和腋芽中显著高于其他组织;不定根发育过程中,miR396家族不同成员表达模式存在显著差异,整体上呈上调表达趋势,其候选靶基因呈下调表达趋势;外源IBA处理显著诱导...     

The acute inhibitory effect of adrenomedullin on hypoxia-induced pulmonary hypertension in rats

AIM:The aim of this study is to investigate the acute inhibitory effects of adrenomedullin(ADM_1-52) on hypoxia pulmonary hypertension and its influence on systemic blood pressure.METHODS:Thirty-six male Wistar rats were divided into two groups. Eighteen were exposed to hypoxia for 21 days as hypoxic pulmonary hypertension group,and another eighteen were kept in ambient as control group. Each group were divided into three subgroups which were injected intravenously with ADM 0.1 nmol/kg, 0.3 nmol/kg, 1 nmol/kg, respectively,then hemodynamic parameters were recorded. Plasma cyclic adenosine 3,5,-monophosphate (cAMP) was measured by radioimmunoassay before,during and after injection of 0.3nmol/kg adrenomedullin(ADM_1-52).RESULTS:Mean pulmonary arterial pressure (mPAP)in the hypoxia and control rats treated with ADM decreased, the fall in hypoxia rats is more obviously than control(P＜0.05), ADM (0.1-0.3 nmol/kg) produced dose-related reductions in mPAP in hypoxia rats(P＜0.05). Mean systemic blood pressure(mSBP) of the rats in both groups decreased in a does-dependent manner, and it was more obvious in control rats. Plasma cAMP is higher in hypoxia group than that in control group.CONCLUSION:ADM depresses the rat hypoxia pulmonary hypertension in short term through, at least partly, cAMP-dependent mechanism.     

Effects of propofol on lung injury and PI3K/Akt pathway in rats after liver ischemia and reperfusion

AIM：To study the effect of propofol on phosphatidylinositol-3 kinase/protein kinase B (PI3K/Akt) signaling pathway in the model of rat lung injury after hepatic ischemia and reperfusion (IR). METHODS：Sixty-six SD rats were randomly divided into 4 groups：sham operation group (n=6), IR group (n=24), propofol group (n=24) and propofol+wortmannin group (n=12). The rats in IR group and propofol group were further divided into 4 subgroups according to the time points of 1 h, 3 h, 6 h and 12 h after reperfusion. The rats in propofol+wortmannin group were also divided into 2 subgroups according to the time points of 3 h and 6 h after reperfusion. The rats in sham group were only dissected porta without ligation. The ligation of hepatic pedicle in the rats in IR group was performed to induce liver ischemia for 30 min and then reperfusion was conduced. The rats in propofol group were given slow injection of propofol (20 mg/kg) from the caudal vein 10 min before ischemia, and then propofol was continuously pumped at dose of 20 mg·kg-1·h-1 until rats' death. Other procedures were the same as the rats in IR group. The rats in propofol+wortmannin group were injected with wortmannin, a blocker of PI3K, at dose of 15 μg/kg before ischemia, and also given the injection of propofol as the rats in propofol group. The lung tissues of the rats were collected at the time points of 1 h, 3 h, 6 h and 12 h after reperfusion. The protein levels of total Akt (t-Akt), phosphorylated Akt (p-Akt) and Bcl-2 in the lung tissues were detected by Western blotting. The apoptotic rate was analyzed by flow cytometry with annexin V-FITC/PI staining. RESULTS：Compared with sham group, the protein levels of p-Akt and Bcl-2, and the cell apoptotic rate in the lung tissues in IR group, propofol group and propofol+wortmannin group increased. Compared with IR group, the protein levels of p-Akt and Bcl-2 increased, and cell apoptotic rate of the lung tissues decreased in propofol group. Compared with propofol group, the protein levels of p-Akt and Bcl-2 decreased, and cell apoptotic rate in the lung tissues increased in propofol+wortmannin group. CONCLUSION：Propofol reduces the lung injury in rats induced by liver ischemia and reperfusion, and its mechanism may be involved in PI3K/Akt signaling pathway.     

Hyperhomocysteinemia induces endothelial dysfunction and aggravates microcirculation dysfunction and microthrombosis

AIM: To establish a microthrombus model by carrageenan (Ca)/ lipopolysaccharides (LPS) intraperitoneal injection in rats with hyperhomocysteinemia (HHcy) and endothelial dysfunction induced by L-methionine intake.METHODS: ① Male Sprague Dawley rats were randomly divided into 2 groups: control and endothelial dysfunction (HHcy) groups. L-methionine was administered by gavage in HHcy group for total 4 weeks.Purified water was administered by gavage in control rats.Plasma Hcy,NO and vWF were examined and the thoracic aorta were excised after 4 weeks of L-methionine treatment to evaluate endothelial function.② Male Sprague Dawley rats were randomly divided into 3 groups to establish a microthrombus formation model with Ca/ LPS: control,microthrombus formation (Ca/LPS) and endothelial dysfunction plus mitoarothrombus formation (HHcy＋Ca/LPS) groups.Control rats were injected with normal saline (NS).Ca/LPS rats were intraperitoneally injected with carrageenan (Ca) and followed by lipopolysaccharides (LPS) 16 h later.HHcy＋Ca/LPS rats were intragastric gavaged by L-methionine for total 4 weeks,and then were injected with Ca/LPS in the same way as Ca/LPS group.Cruor parameters and platelet count were detected at 20 h after LPS or NS injection and the mesentery microcirculation was monitored.Plasma NO and vWF were also detected at 24 h after LPS or NS injection.RESULTS: ① Plasma Hcy concentrations and vWF level were significantly increased in HHcy group,while plasma NO content was significantly decreased compared with that in control group.Endothelial dependent relaxation (EDR) of aortic rings was significantly decreased in HHcy group,suggesting endothelial damage/dysfunction was induced by HHcy.② Mesentery capillary was obviously blocked by microthrombus in Ca/LPS rats and was blocked more seriously in HHcy＋Ca/LPS rats.Cruor parameter results suggested that Ca/LPS rats were in hypercoagulable phase and HHcy＋Ca/LPS rats were in hypocoagulable phase at 20 h after LPS injection.Platelet count and plasma NO content in HHcy＋Ca/LPS group were significantly decreased,while plasma vWF level was significantly increased compared with Ca/LPS group.CONCLUSION: L-methionine intake induces severe HHcy and causes endothelial dysfunction in rats.Microcirculation dysfunction and microthrombosis can be caused by Ca/LPS intraperitoneal injection and may be aggravated by endothelial dysfunction.     

Changes of cortisol content in plasma and hippocampus after focal cerebral ischemia-reperfusion in rats

AIM: To investigate the relationship between glucocorticoid (Gc) and injury of hippocampus neurons and the effect of Gc on dementia episode after cerebral ischemia-reperfusion. METHODS: The rat model of middle cerebral artery occlusion (MACO) was established. Cortisol contents in hippocampus and plasma of the model rats were examined by means of the radioimmunoassay at 2 h, 6 h, 12 h, 24 h after reperfusion. RESULTS: The levels of cortisol content in model group were significantly higher than those in sham group and normal group both in hippocampus and plasma. The highest cortisol content was observed at 6 hours after reperfusion. HE staining showed that the impairment of hippocampus neurons was aggravated progressively with reperfusion interval elongating. CONCLUSION: The increased cortisol in hippocampus and plasma, after 2 h cerebral ischemia and 24 h reperfusion, could aggravate the injury of hippocampus neurons and lead to dementia post stroke.     

Effect of carbon monoxide on permeability of brain blood barrier in cerebral local ischemia rats

AIM:To evaluate the effect of carbon monoxide(CO) on the permeability of brain blood barrier(BBB) in cerebral ischemic rats. METHODS:SD rats were divided into three groups. Saline, hemin or ZnPP were injected intraperitoneally 12 h before middle cerebral artery occlusion (MCAO), respectively. The concentration of blood CO and the permeability of BBB at 24 h after MCAO were measured. RESULTS:The CO concentration in blood in hemin group was higher than that in saline group(P＜0.01), but those in ZnPP group was lower than that in saline group(P＜0.01). In infracted regions, the permeability of BBB in hemin group was lower than that in saline group, and those in ZnPP group was higher than that in saline group (P＜0.05). There was no significant changes in BBB permeability among hemin, ZnPP and saline groups in noninfarcted side(P＞0.05). CONCLUSION:CO reduced the permeability of BBB as a messenger gas molecular when its intrinsic concentration was elevated.     

Role of β-endorphin in the suppression of cellular immunity of rats following trauma-hemorrhagic shock()

AIM: To explore the role of plasma β-endorphin(β-EP) in the suppression of cellular immunity following trauma-hemorrhagic shock(T-HS). METHODS: ① Wistar rats with T-HS were sacrificed at 0 h, 1 h, 3 h, 6 h, 12 h, 24 h after T-HS. Plasma sample was collected and β-EP levels in plasma was measured. Rats with sham-operated were served as the controls. ②In in vitro experiment, splenic cells were isolated and mixed from four normal rats and cocultured with shock plasma (SP) or SP +β-EP antiserum. ConA-induced splenic cell proliferation, IL-2 production, IL-2R expression were examined. RESULTS: ① Levels of plasma β-EP elevated remarkably after T-HS immediately, peaked at 1h , showed decreasing tendency and restored normal 24 h after T-HS. ② Shock plasma significantly suppressed ConA-induced splenic cell function. Levels of plasma β-EP were negatively correlated with spenic cell proliferation and IL-2 production and IL-2R expression. Compared with SP group, splenic cell function elevated markedly in SP + β-EP antiserum group, but still lower than that in controls. CONCLUSION: The elevated plasma β-EP following T-HS was involved in the suppression of cellular immunity.     

Regulation of‘Tiao Gan Fang Yao’on neuroendocrine-immuno-function of bandage-stressed rats

AIM: To investigate the regulation of ‘Tiao Gan Fang Yao’(TGFY) on neuroendocrine-immuno-function of bandage-stressed rat . METHODS:The stressed rat model was made by bandage. RIA was adopted to measure the function of hypothalamus-pitutary-adrenal gland axis (HPAA) of stressed rat. Meanwhile, the immunity of stressed rat and the regulation of TGFY were observed.RESULTS:Bandage stress increased the contents of serum corticosterone(CORT), and ACTH, and hypothalamus corticotropin releasing hormone (P＜0.01 or 0.05), which suggested that the excitability of HPAA was enhanced. In addition, bandage stress reduced spleen lymphocyte proliferation (P＜0.01) and decreased H₂O₂ releasing from the macrophages significantly (P＜0.01). While TGFY could decrease HPAA excitability of bandage-stressed rat and strengthen its immunity. CONCLUSION:TGFY could regulate disorder of neuroendocrine-immuno-function of bandage-stressed rat.     

Influence of predator stress on levels of IL-1β, IL-6 in BALB/C mice with brain asymmetry

AIM: To investigate the influence of predator stress on hypothalamic-pituitary-adrenal (HPA) axis and IL-1β, IL-6 in mice with brain asymmetry. METHODS: By using paw preference test, right-pawed, left-pawed, and ambidextrous-pawed mice model were established. Mice with brain lateralization were exposed to their predator (cat). After acute and chronic predator stress by cats, EIA and ELISA were applied to detect plasma levels of corticosterone (CS), IL-1β and IL-6. RESULTS: (1) The level of plasma CS: in both acute and chronic predator stress group, right-pawed and ambidextrous mice had a higher level than that in their corresponding normal group (P<0.05). Meanwhile, the two groups also showed higher level than left-pawed in acute stress. Compared with the corresponding group under acute stress, left-pawed had much higher level of CS under chronic stress (P<0.05). (2) The level of plasma IL-1β: in normal group, left and right-pawed mice were higher than that in ambidextrous mice (P<0.01), of which left-pawed was the highest. In chronic stress group, the left-pawed exhibited higher level than that in right-pawed mice (P<0.05). (3) The level of IL-6: after chronic predator stress, ambidextrous mice had much higher level than that in other two groups (P<0.05). CONCLUSION: Under predator stress, the HPA axis and plasma proinflammatory cytokines (IL-1β, IL-6) in BALB/C mice were modulated by the brain asymmetrically, and brain lateralization may influence the function of immuno-endocrine network in psychological circumstances.     

Astragaloside Ⅳ inhibits JAK2/STAT3 signaling pathway and alleviates severe acute pancreatitis-associated acute liver injury in rats

AIM: To investigate the effect of astragaloside Ⅳ on severe acute pancreatitis (SAP)-associated acute liver injury in the rats and to explore the underlying mechanisms. METHODS: Male Sprague-Dawley (SD) rats (n=96) were randomly divided into sham-operated group, SAP model group, astragaloside Ⅳ treatment group and AG490 treatment group. SAP model was induced by retrograde injection of 5% sodium taurocholate (1 mL/kg) into the biliopancreatic duct. The rats in astragaloside Ⅳ treatment group were intraperitoneally injected with 20 mg/kg astragaloside Ⅳ, while the rats in AG490 treatment group were injected with 8.0 mg/kg AG490 2 h before sodium taurocholate injection. The rats in sham-operated group and model group received the same volume of saline. The rats were sacrificed at 12 h, 18 h and 24 h after the treatment. The levels of ascites, serum amylase, ALT and AST were detected after the blood samples were collected by the puncture through inferior vena cava. The serum levels of TNF-α, IL-6 and IL-1β were also examined by ELISA. Furthermore, HE staining was used to observe the liver pathological changes, and the protein levels of p-JAK2 and p-STAT3 in the liver were evaluated by Western blot. RESULTS: Compared with sham-operated group, the levels of ascites, serum amylase, ALT, AST, IL-6, TNF-α and IL-1β in the rats in model group were significantly increased, while they were decreased in the rats in astragaloside Ⅳ treatment group and AG490 treatment group compared with the rats in model group. Meanwhile, the phosphorylation levels of JAK2 and STAT3 was significantly increased in model group compared with sham-operated group. The rats in astragaloside Ⅳ treatment group and AG490 treatment group both had a better improvement in the liver injury and lower phosphorylation levels of JAK2 and STAT3.CONCLUSION: Astragaloside Ⅳ exerts a protective effect on pancreatitis-associated acute liver injury in the rats possibly via inhibiting JAK2/STAT3 signaling pathway.     

Dynamic changes of neurokinin A and calcitonin gene-related peptide levels in gastric mucosal and plasma in rats with celiac seawater-immersing trauma

AIM: To observe the dynamic changes of neurokinin A (NKA) and calcitonin gene-related peptide (CGRP) levels in gastric mucosal and plasma in rats after abdominal seawater-immersing trauma, and to investigate the influence of these two sensory neuropeptides on acute gastric mucosal lesion. METHODS: Thirty-two SD rats were randomly divided into four groups (normal group, celiac seawater-immersing trauma 1, 2 and 3 h groups). With emzyoimmunoassay and radioimmunoassay respectively, gastric mucosal and plasma NKA and CGRP levels in rats were measured.RESULTS: Compared with normal rats, with the seawater-immersing time prolonged, gastric mucosal NKA and CGRP levels in rats were progressively decreased (P<0.05), while plasma NKA and CGRP levels significantly elevated. CONCLUSION: Seawater-immersion is a harmful factor, it can lead to elevated plasma NKA and CGRP levels and decrease gastric mucosal NKA and CGRP levels.     

Grape seed proanthocyanidin regulates expression of GSTM through Nrf2 in renal tissues of STZ-induced diabetic rats

AIM: To investigate the potential mechanisms of renoprotective effect of grape seed proanthocyanidin (GSP) on diabetic nephropathy.METHODS: Male Wistar rats were injected with 1% streptozotocin (STZ) intravenously to induce diabetes mellitus (DM). The diabetic rats were randomly divided into 2 groups: diabetes group (DM group) and GSP treatment group (GSP group, GSP 250 mg·kg^-1·d^-1). The normal Wistar rats served as control (C group). Body weight (BW), systolic pressure, kidney weight/body weight (KW/BW), fasting plasma glucose (FPG), blood urea nitrogen (BUN), serum creatinine (SCr), glycosylated hemoglobin (HbA1c) and 24 h urine protein were determined 24 weeks after STZ intervention. The pathological changes of the renal tissues were observed. The protein levels of glutathione S-transferase mu (GSTM) and nuclear factor-erythroid 2-related factor 2 (Nrf2) in the renal tissues were determined by Western blotting and immunohistochemistry. RESULTS: Compared with C group, BW in diabetic rats decreased (P<0.01). The levels of systolic pressure, FPG, HbA1c, KW/BW, 24 h urine protein, BUN and SCr in DM group were higher than those in C group (P<0.01). After treated with GSP, the levels of systolic pressure, KW/BW, 24 h urine protein, BUN and SCr in DM rats were lower than those in DM rats without treatment (P<0.01 or P<0.05). The pathological changes were ameliorated in GSP group. The expression of GSTM and Nrf2 was up-regulated in the kidneys of diabetic rats and down-regulated to the normal levels after GSP treatment. CONCLUSION: The renoprotective effect of GSP is associated with the down-regulation of GSTM through modulating the expression of Nrf2.     

Effect of gold nanoparticles on reversing adriamycin resistance of human hepatocellular carcinoma HepG2/ADM cells

AIM: To investigate whether gold nanoparticles (GNPs) reverses adriamycin (ADM), resistance of human hepatocellular carcinoma drug-resistant cell line HepG2/ADM and to explore the potential mechanism. METHODS: The sensitivities of HepG2 cells and HepG2/ADM cells to ADM were tested by MTT assay before and after GNPs pretreatment. The apoptotic rate was examined by flow cytometry. The concentration of ADM in HepG2/ADM or HepG2 cells was determined by ultraviolet-visible spectrophotometer. The content of glutathione (GSH) in HepG2/ADM or HepG2 cells by DTNB method. RESULTS: The half maximal inhibitory concentrations (IC₅₀) of ADM for HepG2/ADM cells were(29.46±1.73) mg/L and (15.18±0.85) mg/L before and after GNPs pretreatment,respectively. The IC₅₀ of ADM for HepG2 cells was (9.16±2.03) mg/L before pretreatment. The apoptotic rate in GNPs+ADM group was higher than that in ADM group (P<0.05). The concentration of ADM in HepG2/ADM group was lower than that in HepG2 group (P<0.01). After GNPs pretreatment, the concentration of ADM in HepG2/ADM cells was higher than that before pretreatment. The content of GSH in HepG2/ADM group was higher than that in HepG2 group (P<0.01). After GNPs pretreatment, the content of GSH in the HepG2/ADM cells was lower than that before pretreatment. CONCLUSION: Gold nanoparticles can reverse ADM resistance of human hepatocellular carcinoma drug-resistant cell line HepG2/ADM, reduce the content of GSH and increase the concentration of ADM in HepG2/ADM cells.     

Strain difference of susceptibility to caerulein-induced acute pancreatitis in mice

AIM: To study the difference of susceptibility to caerulein-induced acute pancreatitis (AP) among the mice of C57BL/6J, BALB/c and ICR strains.METHODS: Two-month-old female mice of C57BL/6J, BALB/c and ICR strains (12 mice for each strain) were divided into control group (n=6) and experimental group (n=6), respectively. The mice were intraperitoneally injected with caerulein (50 μg/ kg) in 1 h interval for 7 serial injections in total. The mice in control group were treated with saline according to the same procedure in experimental group. The blood samples were collected at 0 h, 3 h, 6 h, 9 h, 12 h and 24 h after the first injection of caerulein or saline for plasma α-amylase and lipase assays. The mice were sacrificed 24 h after AP induction, and the pancreatic tissues were harvested for further investigating the pathological changes and expression of inflammatory factors.RESULTS: After AP induction, the mice of BALB/c and ICR strains demonstrated more dramatic increase in plasma α-amylase activity and lipase activity than those of C57BL/6J mice. C57BL/6J mice showed milder morphological changes and lower expression of inflammatory factors in pancreata than those of BALB/c and ICR mice.CONCLUSION: The mice of C57BL/6J strain have less susceptibility to caerulein-induced AP than that of BALB/c and ICR mice.