Griese M, Griese S, Reinhardt D
Children's Hospital, University of Düsseldorf, FRG.
Eur J Clin Invest. 1990 Jun;20(3):317-22. doi: 10.1111/j.1365-2362.1990.tb01863.x.
In a previous investigation of children infected with pertussis during the first week of paroxysmal stage, we found a 50-75% reduction of the isoprenaline (IPN)-induced cAMP response in peripheral MN leucocytes. In order to characterize these findings further, intact human MN leucocytes from healthy adults were treated with PT in vitro. Basal, as well as prostaglandin E1-stimulated cAMP levels were decreased by PT in a dose-dependent fashion over a range of 0.01 to 1000 ng ml-1 to about 65% of control levels. Stimulation of PT-pretreated cells (100 ng ml-1, 90 min, 37 degrees C) showed significantly reduced IPN and PGE1-induced cAMP accumulation, indicated by a depression and shift of the dose-response curves to the right. In contrast, cAMP generation was unchanged by forskolin, a diterpene that is believed to directly stimulate adenylyl cyclase. The anti-allergic drug ketotifen had no direct effects on basal, IPN or PGE1-induced cAMP responses; however the inhibitory actions of PT pretreatment on cAMP levels were diminished (basal and isoprenaline-stimulated) or reversed (PGE1-stimulated). To further locate the site of impaired cAMP responses, beta-adrenoceptor binding, as well as displacement characteristics of the receptor, were estimated by 125I-cyanopindolol binding to a plasma membrane fraction pretreated with or without PT. No differences in beta-adrenoceptor number or in the affinities of the binding sites could be detected. These data are in close agreement with the findings on MN leucocytes from pertussis-infected children and support the notion of PT-induced impaired signal transduction in the cAMP generating system in human MN leucocytes.
在先前一项针对阵咳期第一周感染百日咳的儿童的研究中，我们发现外周MN白细胞中异丙肾上腺素（IPN）诱导的环磷酸腺苷（cAMP）反应降低了50 - 75%。为了进一步明确这些发现，来自健康成年人的完整人MN白细胞在体外接受了百日咳毒素（PT）处理。在0.01至1000 ng/ml的浓度范围内，PT以剂量依赖的方式使基础以及前列腺素E1刺激的cAMP水平降低至对照水平的约65%。对PT预处理的细胞（100 ng/ml，90分钟，37℃）进行刺激，结果显示IPN和PGE1诱导的cAMP积累显著减少，表现为剂量反应曲线下移并右移。相比之下，毛喉素（一种据信可直接刺激腺苷酸环化酶的二萜类化合物）对cAMP生成没有影响。抗过敏药物酮替芬对基础、IPN或PGE1诱导的cAMP反应没有直接作用；然而，PT预处理对cAMP水平的抑制作用有所减弱（基础和异丙肾上腺素刺激的）或被逆转（PGE1刺激的）。为了进一步确定cAMP反应受损的位点，通过用125I - 氰吲哚洛尔与经或未经PT预处理的质膜部分结合，来估计β - 肾上腺素能受体结合以及受体的置换特性。未检测到β - 肾上腺素能受体数量或结合位点亲和力的差异。这些数据与百日咳感染儿童的MN白细胞的研究结果密切一致，并支持PT诱导人MN白细胞中cAMP生成系统信号转导受损这一观点。
