Antibodies against &-adrenoceptor can be detected in serum of patients with dilated cardiomyopathy (DCM), which have 5-agonist-like activity, and induce a positive chronotropic effect on cardiac myocytes by its pe...Antibodies against &-adrenoceptor can be detected in serum of patients with dilated cardiomyopathy (DCM), which have 5-agonist-like activity, and induce a positive chronotropic effect on cardiac myocytes by its persistence at full strength. Effects of the antibodies against Padrenoceptor from sera of patients with DCM on myocardial cytotoxicity and cytoplasmic free Ca2+-concentration (LCa2+ji) were observed in the cultured single layer SD rat ventricular cells by using the cytotoxicity assay and fluorescent Ca2+- indicat0r fura-2/AM. The positive sera of the anti-&adrenoceptor antibodies from patients with DCM markedly enhanced myocardial [Ca2+]i. Betaloc, a 5, -receptor blocker, might inhibit the increase of the antibody-mediated myocardial [Ca2+]i, and the sera from healthy donors had no effect on myocardial [Ca2+]i,. Our results suggest that the anti-β-adrenoceptor antibody might increase myocardial [Ca2+]i, and result in myocardial damage. The antibodies might activate receptor-gating Ca2+-channel, thereby causing myocardial [Ca2+]i, rise and calcium overload. Early use of betaloc is recommended in the treatment of dilated cardiomyopathy.展开更多
T cell activation and proliferation via CD3-TCR complex were investigated by lymphocyte DNA synthesis in vitro.Several interfering factors were also discussed.The result indicated that lymphocyte activation and prolif...T cell activation and proliferation via CD3-TCR complex were investigated by lymphocyte DNA synthesis in vitro.Several interfering factors were also discussed.The result indicated that lymphocyte activation and proliferation are calciumdependent.A rise of cytoplasmic free Ca2+ quickly following activation with CD3 McAb is mainly due to intracellular mobilization of Ca2+,while lymphocyte proliferation needs both intracellular mobilization of Ca2+ as well as influx of extracellular Ca2+, It was confirmed that CTX sensitive G protein plays a role in regulating T cell proliferation by pretreatment with CTX suppressing lymphocyte H-TdR incorporation obviously.PLC and PKC inhibitor neomycin and P.S.S could also decrease T cell proliferation.展开更多
文摘Antibodies against &-adrenoceptor can be detected in serum of patients with dilated cardiomyopathy (DCM), which have 5-agonist-like activity, and induce a positive chronotropic effect on cardiac myocytes by its persistence at full strength. Effects of the antibodies against Padrenoceptor from sera of patients with DCM on myocardial cytotoxicity and cytoplasmic free Ca2+-concentration (LCa2+ji) were observed in the cultured single layer SD rat ventricular cells by using the cytotoxicity assay and fluorescent Ca2+- indicat0r fura-2/AM. The positive sera of the anti-&adrenoceptor antibodies from patients with DCM markedly enhanced myocardial [Ca2+]i. Betaloc, a 5, -receptor blocker, might inhibit the increase of the antibody-mediated myocardial [Ca2+]i, and the sera from healthy donors had no effect on myocardial [Ca2+]i,. Our results suggest that the anti-β-adrenoceptor antibody might increase myocardial [Ca2+]i, and result in myocardial damage. The antibodies might activate receptor-gating Ca2+-channel, thereby causing myocardial [Ca2+]i, rise and calcium overload. Early use of betaloc is recommended in the treatment of dilated cardiomyopathy.
文摘T cell activation and proliferation via CD3-TCR complex were investigated by lymphocyte DNA synthesis in vitro.Several interfering factors were also discussed.The result indicated that lymphocyte activation and proliferation are calciumdependent.A rise of cytoplasmic free Ca2+ quickly following activation with CD3 McAb is mainly due to intracellular mobilization of Ca2+,while lymphocyte proliferation needs both intracellular mobilization of Ca2+ as well as influx of extracellular Ca2+, It was confirmed that CTX sensitive G protein plays a role in regulating T cell proliferation by pretreatment with CTX suppressing lymphocyte H-TdR incorporation obviously.PLC and PKC inhibitor neomycin and P.S.S could also decrease T cell proliferation.
