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Aim To investigate the effect of orientin on proliferation and differentiation of 3T3-L1 pre-adipocytes and on insulin resistance(IR) in 3T3-L1 adipocytes and the possible mechanisms.Methods MTT assay and oil red O staining were applied to investigate the proliferation and the differentiation of 3T3-L1 pre-adipocytes, respectively.The intracellular triglyceride(TG) contents were detected by enzymatic analysis.IR model was induced with dexamethasone.A fluorescent glucose analogue, 2-NBDG, was used to measure the rate of glucose uptake.Western blot was used to detect the protein level of GLUT4 and phosphorylation of AMPK and ACC.The GLUT4 translocation was measured by fluorescent-immunohistochemistry.Results Orientin decreased the formation of lipid droplets and intracellular TG contents(P<0.01) in a concentration-dependent manner(P<0.05), but it had no obvious effects on the cell vitality.Under the IR state, orientin significantly increased 3T3-L1 adipocytes glucose uptake(P<0.05).Meanwhile, orientin up-regulated the protein expression of p-AMPK, p-ACC, and enhanced GLUT4 translocation and its expression.Conclusion Orientin can effectively inhibit the differentiation of 3T3-L1 pre-adipocytes and increase insulin sensitivity due to the activation of AMPK/GLUT4 signal pathway.
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Sustained hypoxic pulmonary vasoconstriction (HPV ) as experienced at high altitude can lead to hypoxic pulmonary hypertension(HPH).HPV,a special physiological phenomenon of lung,is the physiological reflex of organism in hypoxic envi-ronment.However,in high altitude hypoxic environment,the sustained HPV can lead to pulmonary vascular remodeling and right ventricular hypertrophy,at the same time,the degree of hypoxia in alveoli can be aggravated.Vicious circle of hypoxia is formed,further causing the severe high altitude sickness such as pulmonary edema and pulmonary heart disease.HPV appears in preliminary of HPH,but in the chronic phase,irreversible hy-poxic pulmonary vascular remodeling forms.Therefore,studying the mechanism of HPV and the effect of HPV in HPH can pro-vide targets and ideas for the prevention and treatment of high al-titude sickness. Additionally, in preliminary stage of HPV, prompt treatment is critical for the prevention of high altitude sickness.However,the mechanism of HPV and its roles in HPH are still not fully elucidated in current studies.This paper sum-marizes the studies about HPV in HPH of recent years,aiming to provide references for researchers and clinical treatment in this research field.