AIM:To observe the effect of B-HT933, a selective α2-adrenoceptor agonist, on lipopolysaccha-ride ( LPS )-induced TNF-αproduction in neonatal rat cardiomyocytes and to explore the underlying mechanisms . METHODS:The neonatal rat cardiomyocytes were cultured .The localization of α2A-adrenoceptor in the cardiomyocytes was examined by immunofluorescence staining .The cardiomyocytes were exposed to LPS or/and B-HT933 for different time.The level of TNF-αin the supernatants and the mRNA expression of TNF-αwere detected by ELISA and real-time PCR, respectively.In addition, LPS-associated signal molecules in the cardiomyocytes were also examined by Western blotting.RESULTS: Immunofluorescence staining showed that α2A-adrenoceptors were localized in the cardiomyocytes . LPS stimulated TNF-αproduction in the cardiomyocytes in a dose and time-dependent manner .B-HT933 pretreatment sig-nificantly inhibited the expression of TNF-αat mRNA and protein levels in LPS-treated cardiomyocytes .Furthermore, LPS exposure induced IκBαand p38 phosphorylation in cardiomyocytes and only IκBαphosphorylation was prevented by B-HT933 treatment.CONCLUSION:α2A-adrenoceptors are present in neonatal rat cardiomyocytes and its agonist B -HT933 inhibits LPS-induced TNF-αproduction in cardiomyocytes via suppressing IκBαphosphorylation .

Objective To explore the mediating effect of psychological flexibility in the relationship between the two dimensions of type-D personality(negative affect and social inhibition)and pathological in-ternet use.Methods 592 university students were sampled from central China district and were adminis-tered with Adolescent Pathological Internet Use Scale(APIUS),Type-D personality scale(DS14)and Ac-ceptance and Action Questionnaire-Second Edition(AAQ-Ⅱ).Results Pathological internet use(2.56 ± 0.61)positively correlated with negative affect(1.58±0.78)and social inhibition(1.96±0.61)(r=0.37, 0.25)respectively,and negatively correlated with psychological flexibility(4.69±1.15)(r=-0.40).Path a-nalysis with latent variables showed psychological flexibility partially but significantly mediated the predictive effect of negative affect and social inhibition on pathological internet use.The mediation rates were 56% for negative affect and 62% for social inhibition.Conclusion Psychological flexibility has significant incremen-tal validity beyond two dimensions of type-D personality,and partially mediated the effect of negative affect and social inhibition on pathological internet use.These results suggest the intervention focus of PIU can be psychological flexibility.