Goldman D W, Goetzl E J
J Exp Med. 1984 Apr 1;159(4):1027-41. doi: 10.1084/jem.159.4.1027.
Human polymorphonuclear (PMN) leukocytes bound [3H]leukotriene B4 ([3H]-LTB4) specifically, as assessed by the displacement of 88% or more of the bound radioactivity by a 15,000-fold higher concentration of nonradioactive LTB4 or by micromolar concentrations of structural isomers of LTB4. The specific binding of [3H]LTB4 by PMN leukocytes was characterized by rapid association and dissociation, and was saturable at 800 nM LTB4. The results of computer analyses of the concentration dependence of binding of [3H]LTB4 were consistent with the expression of two classes of receptors having respective mean affinities of 3.9 X 10(-10) M and 6.1 X 10(-8) M and mean densities of 4.4 X 10(3) and 2.7 X 10(5) per PMN leukocyte. Structural isomers of LTB4 inhibited the binding of [3H]LTB4 to PMN leukocytes at concentrations similar to those required to elicit chemotaxis, while chemotactic peptides did not inhibit binding. PMN leukocytes that were deactivated by prior exposure to LTB4 lost high affinity binding sites selectively and concurrently with a reduction in the chemotactic response to LTB4. Chemotactic deactivation altered, but did not eliminate, the low affinity receptors for LTB4 and reduced only minimally the lysosomal degranulation elicited by LTB4. The high affinity receptors for LTB4 on normal human PMN leukocytes appear to transduce the chemotaxis evoked by LTB4 without substantially modifying lysosomal degranulation.
通过15000倍高浓度的非放射性白三烯B4（LTB4）或微摩尔浓度的LTB4结构异构体取代88%或更多的结合放射性来评估，人类多形核（PMN）白细胞特异性结合[3H]白三烯B4（[3H]-LTB4）。PMN白细胞对[3H]LTB4的特异性结合具有快速结合和解离的特点，并且在800 nM LTB4时可饱和。对[3H]LTB4结合浓度依赖性的计算机分析结果与两类受体的表达一致，这两类受体的平均亲和力分别为3.9×10^(-10) M和6.1×10^(-8) M，平均密度分别为每个PMN白细胞4.4×10^3和2.7×10^5。LTB4的结构异构体在引发趋化作用所需的类似浓度下抑制[3H]LTB4与PMN白细胞的结合，而趋化肽不抑制结合。预先暴露于LTB4而失活的PMN白细胞选择性地失去高亲和力结合位点，同时对LTB4的趋化反应降低。趋化失活改变但未消除LTB4的低亲和力受体，并且仅略微降低了LTB4引发的溶酶体脱颗粒。正常人PMN白细胞上LTB4的高亲和力受体似乎在不显著改变溶酶体脱颗粒的情况下转导LTB4诱发的趋化作用。
