Schmidt J, Lindstaedt R, Szelenyi I
Department of Pharmacology, ASTA Pharma AG, Frankfurt, F.R.G.
J Lipid Mediat. 1992 Feb;5(1):13-22.
Guinea-pig alveolar macrophages (AM) exhibited a concentration dependent superoxide anion (.O2-) generation as measured by means of lucigenin-chemiluminescence (CL) in response to platelet-activating factor (PAF) in the range of 1 nM to 100 nM. PAF effects on .O2(-)-generation were specific to the form of PAF that is biologically active in most systems; lyso-PAF had no effect. The CL-response was inhibited following incubation with EDTA (IC50: 859 microM), the intracellular Ca(2+)-antagonist TMB-8 (IC50: 73 microM), or the calmodulin antagonists W-7 (IC50: 13 microM) and trifluoperazine (IC50: 14 microM) indicating the involvement of Ca2+ in the signal transduction pathway. Increasing the intracellular cAMP-levels by PGE2 or forskolin resulted in an inhibition of the CL-response, whereas the beta-adrenoceptor agonist salbutamol showed no effect. On the other hand phosphodiesterase inhibition by IBMX (10 microM: 25%) or zardaverine (10 microM: 29%) also resulted in a transient inhibition of the CL-response. Protein kinase C (PKC) seemed not to be involved in the signal transduction, since the PKC-inhibitors staurosporine, H-7 and D-sphingosine were inactive. In contrast, the PAF receptor antagonists WEB-2086 (IC50: 700 nM) and WEB-2170 (IC50: 176 nM) exerted a strong inhibitory activity. The antiallergic/antiasthmatic drug azelastine also reduced the PAF induced CL-response (IC50: 12 microM), whereas the other antiallergic/antiasthmatic compounds showed almost no inhibition.
豚鼠肺泡巨噬细胞（AM）在1 nM至100 nM范围内，对血小板活化因子（PAF）产生了浓度依赖性的超氧阴离子（.O2-）生成，这是通过光泽精化学发光（CL）测量的。PAF对.O2(-)生成的影响对大多数系统中具有生物活性的PAF形式具有特异性；溶血PAF没有影响。与EDTA（IC50：859 microM）、细胞内Ca(2+)拮抗剂TMB-8（IC50：73 microM）或钙调蛋白拮抗剂W-7（IC50：13 microM）和三氟拉嗪（IC50：14 microM）孵育后，CL反应受到抑制，表明Ca2+参与了信号转导途径。通过PGE2或福斯可林增加细胞内cAMP水平会导致CL反应受到抑制，而β-肾上腺素能受体激动剂沙丁胺醇则没有效果。另一方面，IBMX（10 microM：25%）或扎达维林（10 microM：29%）对磷酸二酯酶的抑制也导致CL反应的短暂抑制。蛋白激酶C（PKC）似乎不参与信号转导，因为PKC抑制剂星形孢菌素、H-7和D-鞘氨醇没有活性。相比之下，PAF受体拮抗剂WEB-2086（IC50：700 nM）和WEB-2170（IC50：176 nM）具有很强的抑制活性。抗过敏/抗哮喘药物氮卓斯汀也降低了PAF诱导的CL反应（IC50：12 microM），而其他抗过敏/抗哮喘化合物几乎没有抑制作用。
