Shalit M, Schwartz L B, Golzar N, vonAllman C, Valenzano M, Fleekop P, Atkins P C, Zweiman B
Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104.
J Immunol. 1988 Aug 1;141(3):821-6.
The patterns of in vivo release of histamine and tryptase were determined during prolonged Ag incubation in atopic individuals, using skin chambers placed over denuded skin blister sites. However, the patterns of histamine and tryptase release over a period of up to 9 h of Ag exposure were different. Whereas rates of release of both histamine and tryptase peaked within 1 h in an Ag dose-response fashion, that of tryptase decreased progressively thereafter and was not different from buffer challenge sites from the 5th to 9th h at all concentrations of Ag tested. The rate of histamine release reached a plateau after 2 h and remained at a constant low level throughout the 3rd to 9th h of Ag incubation. Rechallenge of the sites continuously exposed to Ag with a different second Ag at the 6th h resulted in a second peak of release of both histamine and tryptase. This persistence of in vivo histamine but not tryptase release during the later time points of the cutaneous allergic response differs from what has been demonstrated in vitro with dispersed mast cells. Whether this reflects basophil participation at these time points or an as yet undetermined mechanism for release of histamine but not tryptase by mast cells is not known. These novel patterns of mediator release after prolonged Ag exposure in vivo may have clinical relevance to allergic diseases during which atopic subjects are exposed to Ag over several hours to days.
通过将皮肤小室置于裸露的皮肤水疱部位，测定了特应性个体在长时间抗原孵育期间组胺和类胰蛋白酶的体内释放模式。然而，在长达9小时的抗原暴露期间，组胺和类胰蛋白酶的释放模式有所不同。组胺和类胰蛋白酶的释放速率均在1小时内以抗原剂量反应方式达到峰值，而此后类胰蛋白酶的释放速率逐渐下降，在所有测试的抗原浓度下，从第5小时到第9小时，其释放速率与缓冲液激发部位无差异。组胺释放速率在2小时后达到平台期，并在抗原孵育的第3小时至第9小时一直保持在恒定的低水平。在第6小时，用不同的第二种抗原对持续暴露于抗原的部位进行再次激发，导致组胺和类胰蛋白酶释放出现第二个峰值。在皮肤过敏反应的后期时间点，体内组胺释放持续存在而类胰蛋白酶释放不存在，这与在体外分散肥大细胞中所证明的情况不同。这是否反映了嗜碱性粒细胞在这些时间点的参与，或者是肥大细胞释放组胺而非类胰蛋白酶的尚未确定的机制，目前尚不清楚。体内长时间抗原暴露后这些新型的介质释放模式可能与过敏性疾病具有临床相关性，在这些疾病中，特应性个体在数小时至数天内暴露于抗原。
