Passwell J H, Goldring S R, Dayer J M
Immunology. 1982 Jun;46(2):415-21.
Exposure of human monocytes in monolayer culture to concanavalin A (Con A) or Fc fragments of IgG results in decreased levels of lysozyme, acid phosphatase and the second component of complement (C2), but increased levels of prostaglandin E (PGE) in the culture medium. Indomethacin blocked the effect of Con A and Fc fragments on PGE levels but did not alter the effects on the other secretory products. The addition of Con A to the monocyte cultures resulted in increased cAMP levels in short (<20 min) and in long term incubations (24 hr). Long term exposure to the Fc fragments of IgG also resulted in elevated levels of cAMP. In long term cultures, elevation of cAMP levels by Fc fragments and Con A may in part be mediated by stimulation of endogenous prostaglandin production, since addition of indomethacin resulted in a return of cAMP towards basal levels. The addition of D-L isoproterenol, IBMX, or exogenous PGE, reagents that increase cAMP content, or addition of Dibutyryl 3′, 5′ adenosine monophosphate (DBcAMP) to cultures resulted in a dose-dependent inhibition of secretion of acid phosphatase, lysozyme and C2. These findings suggest that certain secretory responses of human monocytes are reduced by agents which increase cAMP levels. These changes may be related to direct effects on adenylate cyclase stimulation or indirect effects on the release of other products which effect cAMP generation. These changes in cAMP content may in part be responsible for the reduced secretory response.
将人单核细胞单层培养物暴露于伴刀豆球蛋白A（Con A）或IgG的Fc片段中，会导致溶菌酶、酸性磷酸酶和补体第二成分（C2）水平降低，但培养基中前列腺素E（PGE）水平升高。吲哚美辛可阻断Con A和Fc片段对PGE水平的影响，但不会改变对其他分泌产物的影响。向单核细胞培养物中添加Con A会导致短期（<20分钟）和长期培养（24小时）中cAMP水平升高。长期暴露于IgG的Fc片段也会导致cAMP水平升高。在长期培养中，Fc片段和Con A引起的cAMP水平升高可能部分是由内源性前列腺素产生的刺激介导的，因为添加吲哚美辛会导致cAMP水平恢复到基础水平。添加D-L异丙肾上腺素、异丁基甲基黄嘌呤（IBMX）或外源性PGE（这些试剂可增加cAMP含量），或向培养物中添加二丁酰3′,5′-腺苷单磷酸（DBcAMP），会导致酸性磷酸酶、溶菌酶和C2分泌呈剂量依赖性抑制。这些发现表明，人单核细胞的某些分泌反应会被增加cAMP水平的试剂所降低。这些变化可能与对腺苷酸环化酶刺激的直接作用或对影响cAMP生成的其他产物释放的间接作用有关。cAMP含量的这些变化可能部分导致了分泌反应的降低。
