Sempere Telésfora, Urbina Mary, Lima Lucimey
Laboratorio de Neuroquímica, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela.
Neuroimmunomodulation. 2004;11(5):307-15. doi: 10.1159/000079411.
Lymphocytes possess serotonin 5-HT(1A) and beta-adrenergic receptors, which have been related to cell proliferation. In the present report, lymphocytes of rat blood were isolated by Ficoll-Hypaque gradients and differential adhesion to plastic. They were cultured in RPMI medium for 72 h in the presence of the mitogens lipopolysaccharide concanavalin A and anti-CD3 antibody. The latter two stimulated the proliferation of lymphocytes, but not the first. Serotonin (0.1-100 microM) was added alone or in the presence of suboptimal concentrations of concanavalin A (2 microg/ml) or anti-CD3 antibody (0.4 microg/ml). The 5-HT(1A) receptor agonists, 8-hydroxy-2-(di-n-propylamino)tetralin and buspirone (0.1-100 microM) were also tested in the cultures. Serotonin, 8-hydroxy-2-(di-n-propylamino)tetralin and buspirone neither had any effect by themselves, nor modified the proliferation induced by the mitogens. Noradrenaline (25-1,000 microM) and the beta-adrenergic receptor agonist, isoproterenol (5-100 microM), produced a reduction of the activation induced by concanavalin A or anti-CD3 antibody in a dose-dependent manner. Increasing serotonin concentrations reduced the inhibitory effect of noradrenaline (300 microM). Variable concentrations of 8-hydroxy-2-(di-n-propylamino)tetralin or buspirone also reduced the inhibition produced by isoproterenol (100 microM). The antagonist of 5-HT(1A) receptors, WAY-100,478 (0.1-100 microM), inhibited concanavalin A- or anti-CD3 antibody-induced proliferation. Serotonin (0.1-100 microM) impaired the inhibitory effect of the 5-HT(1A) antagonist (10 microM). The inhibitor of tryptophan hydroxylase, p-chlorophenylalanine (50-1,000 microM), decreased the stimulatory effect of concanavalin A, serotonin (0.5-100 microM) and 8-hydroxy-2-(di-n-propylamino)tetralin (1-100 microM) reverted the effect of p-chlorophenylalanine (1,000 microM). The serotonin reuptake blockers zimelidine, imipramine and clomipramine decreased concanavalin A-induced proliferation. The concentrations of serotonin and noradrenaline increased in lymphocytes cultured in the presence of concanavalin A, probably as a mechanism for modifying the final effect on proliferation. The present results indicate that 5-HT(1A) receptors play a stimulatory role on rat blood lymphocytes, and they interact in a parallel and opposite manner with beta-adrenergic receptors. Furthermore, endogenous serotonin is relevant in displaying its stimulatory effect.
淋巴细胞具有5-羟色胺5-HT(1A)和β-肾上腺素能受体，这些受体与细胞增殖有关。在本报告中，通过Ficoll-Hypaque梯度离心法和对塑料的差异黏附作用分离大鼠血液中的淋巴细胞。将它们在RPMI培养基中，于有丝分裂原脂多糖、伴刀豆球蛋白A和抗CD3抗体存在的情况下培养72小时。后两者刺激淋巴细胞增殖，但脂多糖不能。单独添加5-羟色胺（0.1 - 100微摩尔）或在次优浓度的伴刀豆球蛋白A（2微克/毫升）或抗CD3抗体（0.4微克/毫升）存在的情况下添加。还在培养物中测试了5-HT(1A)受体激动剂8-羟基-2-（二正丙基氨基）四氢萘和丁螺环酮（0.1 - 100微摩尔）。5-羟色胺、8-羟基-2-（二正丙基氨基）四氢萘和丁螺环酮自身均无任何作用，也未改变有丝分裂原诱导的增殖。去甲肾上腺素（25 - 1000微摩尔）和β-肾上腺素能受体激动剂异丙肾上腺素（5 - 100微摩尔）以剂量依赖方式降低伴刀豆球蛋白A或抗CD3抗体诱导的活化作用。增加5-羟色胺浓度可降低去甲肾上腺素（300微摩尔）的抑制作用。不同浓度的8-羟基-2-（二正丙基氨基）四氢萘或丁螺环酮也可降低异丙肾上腺素（100微摩尔）产生的抑制作用。5-HT(1A)受体拮抗剂WAY-100,478（0.1 - 100微摩尔）抑制伴刀豆球蛋白A或抗CD3抗体诱导的增殖。5-羟色胺（0.1 - 100微摩尔）削弱5-HT(1A)拮抗剂（10微摩尔）的抑制作用。色氨酸羟化酶抑制剂对氯苯丙氨酸（50 - 1000微摩尔）降低伴刀豆球蛋白A的刺激作用，5-羟色胺（0.5 - 100微摩尔）和8-羟基-2-（二正丙基氨基）四氢萘（1 - 100微摩尔）可逆转对氯苯丙氨酸（1000微摩尔）的作用。5-羟色胺再摄取阻滞剂齐美利定、丙咪嗪和氯米帕明降低伴刀豆球蛋白A诱导的增殖。在伴刀豆球蛋白A存在的情况下培养的淋巴细胞中5-羟色胺和去甲肾上腺素浓度升高，这可能是改变对增殖最终作用的一种机制。目前的结果表明5-HT(1A)受体对大鼠血液淋巴细胞起刺激作用，并且它们与β-肾上腺素能受体以平行且相反的方式相互作用。此外，内源性5-羟色胺在发挥其刺激作用方面具有相关性。
