Amrani Y, Da Silva A, Kassel O, Bronner C
Laboratoire de Neuroimmunopharmacologie, Faculté de Pharmacie, INSERM CJF 91-05, Université Louis Pasteur I, Illkirch, France.
Naunyn Schmiedebergs Arch Pharmacol. 1994 Dec;350(6):662-9. doi: 10.1007/BF00169372.
The effects of bradykinin (BK) and histamine on intracellular Ca2+ ([Ca2+]i) were studied in fura-2-loaded guinea-pig tracheal smooth muscle cells in culture. BK, at 10 nM, and histamine, at 100 microM, induced a rise in [Ca2+]i which was inhibited by the B2 antagonist Hoe 140 and by the H1 antagonist triprolidine, respectively. This rise in [Ca2+]i is biphasic, consisting of a rapid transient phase followed by a sustained phase. The transient phase, induced by either BK or histamine, was strongly inhibited by thapsigargin, a microsomal Ca(2+)-ATPase inhibitor, usually used to deplete certain intracellular Ca(2+)-stores. Ni2+ (4 mM) did not affect the transient phase but abolished the sustained phase when cells were stimulated by BK, further supporting the fact that the transient phase was only dependent on intracellular Ca2+ pools. The sustained phase was partially (for BK) and completely (for histamine) inhibited by 30 microM Mn2+. This effect could be completely reversed by the addition of DTPA, a cell-impermeant chelator of Mn2+, indicating that the Mn2+ exerted its effect extracellularly. The presence of 1 mM probenecid (an inhibitor of a membrane organic anion transporter that extrudes fura-2) drastically inhibited the sustained phase by more than 77% for BK and 88% for histamine. Our results suggest that the effects of BK and histamine on airway smooth muscle cells are mediated via bradykinin B2 receptors and histamine H1 receptors, respectively whose activation allows the rapid transient rise in [Ca2+]i from thapsigargin-sensitive intracellular Ca2+ pools. The sustained phase is proposed to be drastically influenced by an acceleration of fura-2 extrusion during the increase of [Ca2+]i via a probenecid-sensitive mechanism.
在培养的用fura - 2负载的豚鼠气管平滑肌细胞中研究了缓激肽（BK）和组胺对细胞内钙离子浓度（[Ca2+]i）的影响。10 nM的BK和100 μM的组胺均可诱导[Ca2+]i升高，分别被B2拮抗剂Hoe 140和H1拮抗剂曲普利啶抑制。这种[Ca2+]i升高呈双相性，包括快速瞬态期和持续期。由BK或组胺诱导的瞬态期被毒胡萝卜素强烈抑制，毒胡萝卜素是一种微粒体Ca(2+)-ATP酶抑制剂，通常用于耗尽某些细胞内钙库。4 mM的Ni2+不影响瞬态期，但在细胞受BK刺激时消除了持续期，进一步支持了瞬态期仅依赖于细胞内钙库的事实。30 μM的Mn2+对BK诱导的持续期有部分抑制作用，对组胺诱导的持续期则完全抑制。加入二乙三胺五乙酸（DTPA，一种不能透过细胞膜的Mn2+螯合剂）可使这种作用完全逆转，表明Mn2+在细胞外发挥作用。1 mM丙磺舒（一种膜有机阴离子转运体抑制剂，可使fura - 2排出细胞）的存在对BK诱导的持续期有超过77%的显著抑制作用，对组胺诱导的持续期有88%的显著抑制作用。我们的结果表明，BK和组胺对气道平滑肌细胞的作用分别通过缓激肽B2受体和组胺H1受体介导，其激活使[Ca2+]i从对毒胡萝卜素敏感的细胞内钙库快速瞬态升高。持续期被认为是通过丙磺舒敏感机制在[Ca2+]i升高期间fura - 2排出加速而受到显著影响。
