Turner M W, Barnett G E, Strobel S
Department of Immunology, Institute of Child Health, London, U.K.
Clin Exp Allergy. 1990 Jul;20(4):421-7. doi: 10.1111/j.1365-2222.1990.tb02804.x.
Groups of rats previously sensitized systemically on day 0 with a low dose of ovalbumin (OVA) were gavaged daily with ovalbumin or bovine serum albumin or a mixture of both proteins from day 14 to 18. Blood samples were obtained pre- and post-challenge and serum levels of the rat mast cell protease II (RMCPII) determined by immunoassay. Release of this specific mucosal mast cell mediator was only observed in animals challenged with ovalbumin and the initial challenge released levels of RMCPII 15-fold higher than normal resting levels (P less than 0.001). Subsequent daily challenges evoked the release of significantly lower levels of mediator (P less than 0.001 relative to day 14), but with one exception each test group released significantly more RMCPII than the matched control group on each day (P less than 0.001-P = 0.015). An increased uptake of BSA 'bystander' protein was observed when OVA-sensitized animals were repeatedly gavage-challenged with OVA but there was no correlation with the release of RMCPII mediator. After a 9-day rest period the levels of RMCPII released 6 hr post-challenge on day 26 were still significantly lower (P = 0.004) than the levels of mediator released on day 14. In contrast, animals not previously challenged were still capable of releasing high levels of mediator at the time of first mucosal contact. The levels of RMCPII detected in the serum after enteral protein antigen challenge never exceeded 6000 ng/ml and were lower than those previously observed in parasitized rats following intravenous antigen challenge.
在第0天用低剂量卵清蛋白（OVA）进行全身致敏的大鼠组，从第14天至18天每天经口灌胃给予卵清蛋白或牛血清白蛋白或两种蛋白质的混合物。在激发前后采集血样，并通过免疫测定法测定大鼠肥大细胞蛋白酶II（RMCPII）的血清水平。仅在接受卵清蛋白激发的动物中观察到这种特异性黏膜肥大细胞介质的释放，并且初次激发释放的RMCPII水平比正常静息水平高15倍（P小于0.001）。随后的每日激发引起的介质释放水平显著降低（相对于第14天，P小于0.001），但每个测试组除一个例外，在每天释放的RMCPII均显著多于匹配的对照组（P小于0.001 - P = 0.015）。当用OVA对OVA致敏的动物进行反复灌胃激发时，观察到BSA“旁观者”蛋白的摄取增加，但与RMCPII介质的释放没有相关性。在9天的休息期后，第26天激发后6小时释放的RMCPII水平仍显著低于第14天释放的介质水平（P = 0.004）。相比之下，未预先激发的动物在首次黏膜接触时仍能够释放高水平的介质。肠内蛋白抗原激发后血清中检测到的RMCPII水平从未超过6000 ng/ml，且低于先前在静脉内抗原激发后寄生虫感染大鼠中观察到的水平。
