Nowak D, Bialasiewicz P, Antczak A, Krol M, Piasecka G
Department of Pneumonology and Allergology, Medical University of Lodz, Poland.
Immunobiology. 1995 Apr;192(5):343-52. doi: 10.1016/S0171-2985(11)80174-9.
A rapid transient rise in the intracellular free calcium concentration ( Ca2+]i) is an important step in human polymorphonuclear leukocytes (PMNL) activation. This can be caused by many inflammatory mediators and has been implicated in the regulation of various cellular reactions. In this study we investigated the changes of [Ca2+]i in human PMNL activated three times with 10(-7)M n-formyl-methionyl-leucyl-phenylalanine (FMLP). PMNL in the presence of 1 mM Ca2+ were able to respond to three consecutive stimulations with FMLP. The first Ca2+ response was the highest one and was a result of Ca2+ release from internal stores (which was responsible for about 30% of maximal increment in [Ca2+]i) and the extracellular Ca2+ influx. Experiments with PMNL suspended in a medium containing 100 nM Ca2+ and pretreated with 1 nM Ni2+ (an inorganic calcium channel blocker) revealed that the second and third response is completely dependent on the extracellular Ca2+ influx. Changes of the time interval between stimulations had no influence on the occurrence of extracellular Ca2+ influx related to second addition of FMLP. Elongation of the time interval up to 30 min did not restore the release of Ca2+ from internal stores. It indicates the occurrence of dissociation of Ca2+ release from intracellular stores and extracellular Ca2+ influx during the second and third PMNL response to FMLP.
细胞内游离钙浓度（[Ca2+]i）的快速短暂升高是人类多形核白细胞（PMNL）激活的重要步骤。这可由多种炎症介质引起，并与各种细胞反应的调节有关。在本研究中，我们研究了用10（-7）M N-甲酰甲硫氨酰-亮氨酰-苯丙氨酸（FMLP）三次激活人PMNL时[Ca2+]i的变化。在1 mM Ca2+存在下的PMNL能够对FMLP的三次连续刺激做出反应。第一次Ca2+反应最高，是细胞内储存释放Ca2+（约占[Ca2+]i最大增量的30%）和细胞外Ca2+内流的结果。用悬浮在含有100 nM Ca2+的培养基中并用1 nM Ni2+（一种无机钙通道阻滞剂）预处理的PMNL进行的实验表明，第二次和第三次反应完全依赖于细胞外Ca2+内流。刺激之间时间间隔的变化对与第二次添加FMLP相关的细胞外Ca2+内流的发生没有影响。将时间间隔延长至30分钟并不能恢复细胞内储存中Ca2+的释放。这表明在PMNL对FMLP的第二次和第三次反应期间，细胞内储存释放Ca2+和细胞外Ca2+内流发生了解离。
