OBJECTIVE: To investigate the effects of simulated hypobaric hypoxia environment at 7 000 m above sea level on cardiac structure and function in rats. METHODS: A total of 96 male SD rats were randomly divided into high-altitude hypobaric hypoxia group (hypoxia group) and normobaric normoxia group (control group). Rats of hypoxia group were placed in a large cabin simulated 7 000 m high-altitude hypobaric hypoxia environment. Operating time 23 h / d, the control circadian ratio of approximately 12 h:12 h. The rats in control group were bred under normobaric normoxia. The hypoxic group was divided into 3 d, 7 d, 14 d, 28 d groups according to hypoxic time, 12 rats in each group. Changes of structure and function of heart due to hypoxia were evaluated by echocardiography and electrocardiogram. Myocardial pathological changes were analyzed by hematoxylin-eosin staining(HE). RESULTS: Compared with the control group at the same time point ①With prolonged exposure to hypobaric hypoxia, the growth ratio of body mass in rats is slower. Arterial oxygen saturation was significantly lower in both 14 d and 28 d (P＜0.05). ② Left ventricular end-diastolic anterior wall thickness (LVAWD) and left ventricular end-diastolic posterior wall thickness (LVPWD) of rats in 28 d were increased significantly (P＜0.05). Left ventricular end-diastolic diameter (LVIDD) and left ventricular internal dimension systole (LVIDS) of rats in 28 d were decreased significantly (P＜0.05, P＜0.01). Left ventricular ejection fraction (EF), fractional shortening of left ventricle (FS), pulmonary vein (PV) peak velocity and PV peak gradient of rats in 7 d were decreased significantly (P＜0.05, P＜0.01). ③The QRS and QT interval period were significantly prolonged in 14 d and 28 d (P＜0.05, P＜0.01). The ST was significantly lower in 3 d and 7 d (P＜0.05, P＜0.01). The amplitude of R wave gradually shifted downward in 7 d, 14 d, 28 d (P＜0.05, P＜0.01). ④The red blood cell (RBC), hemoglobin (HGB), red blood cell distribution width (RDW) in hypoxic group were increased significantly (P＜0.01). The platelet count (PLT) count was decreased significantly in 14 d and 28 d (P＜0.01). The serum creatinine (CR) was increased significantly in 14 d and 28 d (P＜0.05). ⑤Pathological changes such as myocardial edema, sarcolemma condensate, focal degeneration and necrosis with inflammatory cell infiltration could be found at early stage of hypoxia. Myocardial compensatory repair such as myocardial fibroblasts proliferation was significant at end stage of hypoxia. CONCLUSION Left ventricular systolic functions of rats were decreased significantly after exposure to high altitude hypoxia hypobaric. The left ventricular systolic functions would recovery compensatory after one week exposed to high altitude hypoxia hypobaric.
Altitude ; Animals ; Heart ; physiopathology ; Hypoxia ; Male ; Rats ; Rats, Sprague-Dawley

Houttuynia cordata polysaccharide (HCP) is extracted from Houttuynia cordata, a key traditional Chinese medicine. The study was to investigate the effects of HCP on intestinal barrier and microbiota in H1N1 virus infected mice. Mice were infected with H1N1 virus and orally administrated HCP at a dosage of 40 mg(kg(d. H1N1 infection caused pulmonary and intestinal injury and gut microbiota imbalance. HCP significantly suppressed the expression of hypoxia inducible factor-1α and decreased mucosubstances in goblet cells, but restored the level of zonula occludens-1 in intestine. HCP also reversed the composition change of intestinal microbiota caused by H1N1 infection, with significantly reduced relative abundances of Vibrio and Bacillus, the pathogenic bacterial genera. Furthermore, HCP rebalanced the gut microbiota and restored the intestinal homeostasis to some degree. The inhibition of inflammation was associated with the reduced level of Toll-like receptors and interleukin-1β in intestine, as well as the increased production of interleukin-10. Oral administration of HCP alleviated lung injury and intestinal dysfunction caused by H1N1 infection. HCP may gain systemic treatment by local acting on intestine and microbiota. This study proved the high-value application of HCP.
Animals ; Cytokines ; metabolism ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; therapeutic use ; Gastrointestinal Microbiome ; drug effects ; Houttuynia ; chemistry ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Inflammation ; drug therapy ; pathology ; Influenza A Virus, H1N1 Subtype ; pathogenicity ; Intestinal Mucosa ; drug effects ; metabolism ; microbiology ; pathology ; Lung ; drug effects ; metabolism ; pathology ; Male ; Mice, Inbred BALB C ; Orthomyxoviridae Infections ; drug therapy ; pathology ; physiopathology ; Plant Extracts ; chemistry ; Polysaccharides ; chemistry ; pharmacology ; therapeutic use ; Toll-Like Receptors ; metabolism ; Zonula Occludens-1 Protein ; metabolism

Activation of peripheral respiratory chemoreceptors provokes respiratory and cardiovascular reflexes, providing a novel understanding of pathogenic mechanism of hypertension. Here we hypothesize that activation of peripheral respiratory chemoreceptors by hypoxia causes enhanced cardiorespiratory activity in conscious spontaneously hypertensive rats (SHRs). Using whole body plethysmography in combination with radio telemetry, pulmonary ventilation, arterial blood pressure and heart rate were examined in SHRs and Wistar-Kyoto (WKY) rats. We found that exposure to hypoxia induced greater increases in tidal volume and minute ventilation volume in SHRs compared to WKY rats. In addition, hypoxia caused a robust increase in arterial blood pressure and heart rate in SHRs relative to WKY counterparts. After carotid body denervation, the hypoxic ventilatory response was significantly decreased in both SHRs and WKY rats, but without significant difference between the two strains; moreover, the differences of arterial blood pressure and heart rate changes during hypoxic exposure were statistically insignificant between SHRs and WKY rats. It is concluded that hypoxia remarkably potentiates cardiorespiratory activity in the SHRs, suggesting an enhanced sensitivity of carotid bodies to hypoxia.
Animals ; Blood Pressure ; Heart Rate ; Hypertension ; physiopathology ; Hypoxia ; physiopathology ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY

OBJECTIVE: To explore the effects of hydrogen on liver injury in chronic intermittent hypoxia rats and the related oxidative stress mechanism. METHODS: Twenty-four male adult SD rats were randomly divided into 3 groups(=8):the normoxia group (Norm), the chronic intermittent hypoxia group (CIH), the chronic intermittent hypoxia and hydrogen group (H + CIH). Rats in Norm group were exposed in air, those in the other 2 groups suffered from chronic intermittent hypoxia conditions for 5 weeks. Before the CIH treatment, rats in H+CIH group inhaled hydrogen gas at 67% concentration for 1 hour. The serum biochemical indicators of oxidative stress, pro-inflammatory cytokine, liver enzyme and blood lipid were inspected after five weeks treatment, the pathological changes of liver tissue were also observed in the transmission electron microscope. RESULTS: Compared with Norm group, the microstructure of liver cells was severely injured, and the serum levels of glutamic-pyruvic transaminase(ALT),glutamic-oxalacetic transaminase (AST) were significantly higher in CIH group (<0.05); the serum level of 8-hydroxy-2 deoxyguanosine(8-OHdG) and interleukin-6(IL-6) was significantly higher, the serum level of superoxide dismutase (SOD) was significantly lower. Compared with CIH group, the pathology of liver microstructure were significantly improved and the serum levels of ALT, AST were significantly lower in H+CIH group (<0.05); the serum levels of 8-OHdG and IL-6 were significantly lower, the serum level of SOD was significantly higher. Compared with Norm group, the serum level of IL-1 was higher, the serum level of TC, TG, and low density lipoprotein(LDL) were lower, but there was no statistical difference with those in CIH group. There was no statistical difference in the serum level of high density lipoprotein (HDL)among the three groups. CONCLUSIONS Pre-treatment with hydrogen could improve the liver injury caused by chronic intermittent hypoxia, and reducing oxidative stress level for protecting the liver cells damage.
Animals ; Hydrogen ; pharmacology ; Hypoxia ; physiopathology ; Liver ; physiopathology ; Liver Diseases ; therapy ; Male ; Oxidative Stress ; Random Allocation ; Rats ; Rats, Sprague-Dawley

A 68-year-old man presented with a three-week history of rapidly progressive dementia, gait ataxia and myoclonus. Subsequent electroencephalography showed periodic sharp wave complexes, and cerebrospinal fluid assay revealed the presence of a 14-3-3 protein. A probable diagnosis of sporadic Creutzfeldt-Jakob disease was made, which was further supported by magnetic resonance (MR) imaging of the brain showing asymmetric signal abnormality in the cerebral cortices and basal ganglia. The aetiology, clinical features, diagnostic criteria, various MR imaging patterns and radiologic differential diagnosis of sporadic Creutzfeldt-Jakob disease are discussed in this article.
Aged ; Brain ; pathology ; Cerebral Cortex ; Cerebrospinal Fluid ; metabolism ; Creutzfeldt-Jakob Syndrome ; diagnostic imaging ; Dementia ; physiopathology ; Diagnosis, Differential ; Diffusion Magnetic Resonance Imaging ; Electroencephalography ; Humans ; Hypoxia-Ischemia, Brain ; diagnostic imaging ; Male ; Prion Diseases ; physiopathology

OBJECTIVETo investigate mitophagy in an animal model of hypoxic-ischemic brain damage (HIBD) and its role in HIBD.

METHODSA total of 120 neonatal Sprague-Dawley rats aged 7 days were divided into three groups: sham-operation, HIBD, and autophagy inhibitor intervention (3MA group). The rats in the HIBD group were treated with right common carotid artery ligation and then put in a hypoxic chamber (8% oxygen and 92% nitrogen) for 2.5 hours. Those in the 3MA group were given ligation and hypoxic treatment at 30 minutes after intraperitoneal injection of 2 μL 3MA. Those in the sham-operation group were not given ligation or hypoxic treatment. Single cell suspension was obtained from all groups after model establishment. Immunofluorescence localization was performed for mitochondria labeled with MitoTracker, autophagosomes labeled with LysoTracker, and autophagy labeled with LC3 to observe mitophagy. After staining with the fluorescent probe JC-1, flow cytometry was used to measure mitochondrial membrane potential. TTC staining was used to measure infarct volume. Cytoplasmic proteins in cortical neurons were extracted, and Western blot was used to measure the expression of mitophagy-related proteins.

RESULTSCompared with the sham-operation group, the HIBD group had a significant reduction in mitochondrial membrane potential (P<0.05), a significant increase in mitophagy (P<0.05), a significant increase in the expression of the proteins associated with the division of the mitochondrial Drp1 and Fis1 (P<0.05), and a significant reduction in the expression of the mitochondrial outer membrane protein Tom20 and the mitochondrial inner membrane protein Tim23 (P<0.05). Compared with the HIBD group, the 3MA group had a significantly greater reduction in mitochondrial membrane potential (P<0.05), but showed significantly reduced mitophagy (P<0.05). In addition, the 3MA group had a significantly increased degree of cerebral infarction compared with the HIBD group (P<0.05).

CONCLUSIONSHIBD can increase the degree of mitophagy, and the inhibition of mitophagy can aggravate HIBD in neonatal rats.

Animals ; Animals, Newborn ; Female ; Hypoxia-Ischemia, Brain ; etiology ; physiopathology ; Male ; Mitochondrial Degradation ; physiology ; Rats ; Rats, Sprague-Dawley

Autophagy is a highly evolutionarily conserved physiological mechanism of organism, including several stages such as autophagosomes formation, the fusion of lysosomes and autophagosomes, and autophagosomes degradation. In physiological conditions, autophagy is responsible for clearing the spoiled organelles and long-lived proteins to maintain the homeostasis of cells and organism. Meanwhile, autophagy is also involved in the formation and development of diseases, but the mechanism has not been confirmed yet. The relationship between autophagy and hypoxic ischemic brain injuries represented by stroke is a research hotpot in recent years, but there is no clear conclusion about autophagy's role and mechanism in hypoxic ischemic brain injuries. We reviewed the activation, function and mechanism of autophagy in hypoxic ischemic brain injuries, in order to provide some perspectives on these researches.
Animals ; Autophagy ; Homeostasis ; Humans ; Hypoxia-Ischemia, Brain ; physiopathology ; Lysosomes

The present study was to investigate the role of TRPC6 in pulmonary artery smooth muscle cells (PASMCs) proliferation and apoptosis under hypoxia and hypercapnia. PASMCs were isolated from chloral hydrate-anesthetized male Sprague-Dawley (SD) rats. Cellular purity was assessed by immunofluorescence staining for smooth muscle α-actin under fluorescence microscopy. Passage 4-6 PASMCs were starved for 24 h in serum-free DMEM and divided into 5 groups randomly: normoxia, hypoxia and hypercapnia, DMSO, TRPC6 inhibitor SKF-96365 and TRPC6 activator OAG groups. The normoxic group was incubated under normoxia (5% CO, 21% O, 37 °C) for 24 h, and the others were incubated with corresponding drugs under hypoxic and hypercapnic (6% CO, 5% O, 37 °C) atmosphere for 24 h. TRPC6 mRNA was detected by reverse transcription-PCR. TRPC6 protein was detected by Western blotting. The proliferation of PASMCs was performed by CCK-8 kit. Apoptosis of the PASMCs was detected using TUNEL assay. The [Ca]in the PASMCs was measured using Fura 2-AM fluorescence. The results showed that the expressions of TRPC6 mRNA and protein, and [Ca]were upregulated under hypoxic and hypercapnic conditions. Hypoxia and hypercapnia promoted cellular proliferation and inhibited apoptosis in the PASMCs. OAG enhanced the above-mentioned effects of hypoxia and hypercapnia, whereas SKF-96365 reversed these effects. These results suggest that TRPC6 may play a role in PASMCs proliferation and apoptosis under hypoxia and hypercapnia by regulating [Ca].
Actins ; Animals ; Apoptosis ; Calcium ; metabolism ; Cell Hypoxia ; Cell Proliferation ; Cells, Cultured ; Hypercapnia ; physiopathology ; Imidazoles ; Male ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; metabolism ; Pulmonary Artery ; cytology ; Rats ; Rats, Sprague-Dawley ; TRPC Cation Channels ; metabolism

Considering the great potential of natural products as anticancer agents, the present study was designed to explore the molecular mechanisms responsible for anticancer activities of Mesua ferrea stem bark extract against human colorectal carcinoma. Based on MTT assay results, bioactive sub-fraction (SF-3) was selected for further studies using HCT 116 cells. Repeated column chromatography resulted in isolation of less active α-amyrin from SF-3, which was identified and characterized by GC-MS and HPLC methods. α-amyrin and betulinic acid contents of SF-3 were measured by HPLC methods. Fluorescent assays revealed characteristic apoptotic features, including cell shrinkage, nuclear condensation, and marked decrease in mitochondrial membrane potential in SF-3 treated cells. In addition, increased levels of caspases-9 and -3/7 levels were also observed in SF-3 treated cells. SF-3 showed promising antimetastatic properties in multiple in vitro assays. Multi-pathway analysis revealed significant down-regulation of WNT, HIF-1α, and EGFR with simultaneous up-regulation of p53, Myc/Max, and TGF-β signalling pathways in SF-3 treated cells. In addition, promising growth inhibitory effects were observed in SF-3 treated HCT 116 tumour spheroids, which give a hint about in vivo antitumor efficacy of SF-3 phytoconstituents. In conclusion, these results demonstrated that anticancer effects of SF-3 towards colon cancer are through modulation of multiple molecular pathways.
Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Colorectal Neoplasms ; drug therapy ; metabolism ; pathology ; physiopathology ; ErbB Receptors ; genetics ; metabolism ; HCT116 Cells ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; genetics ; metabolism ; Magnoliopsida ; chemistry ; Neoplasm Metastasis ; prevention & control ; Plant Bark ; chemistry ; Plant Extracts ; pharmacology ; Signal Transduction ; drug effects ; Wnt Proteins ; genetics ; metabolism

Under hypoxia condition, microRNA （miRNA） can interact with transcription factors for regulating the cell metabolism, angiogenesis, erythropoiesis, cellular proliferation, differentiation and apoptosis. The biological processes above may play an important role in mechanical asphyxia death. This article reviews the regulating function of miRNA under hypoxia condition and the influence of hypoxia to biosynthesis of miRNA, which may provide some new ideas to the research of miRNA on determining the cause of mechanical asphyxia death in the field of forensic medicine.
Accidents ; Airway Obstruction/physiopathology* ; Apoptosis ; Asphyxia/pathology* ; Cause of Death ; Death ; Forensic Medicine ; Humans ; Hypoxia/physiopathology* ; MicroRNAs/metabolism* ; Oxygen