Farsky S H P, Borelli P, Fock R A, Proto S Z, Ferreira J M C, Mello S B V
Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, Av. Prof. Lineu Prestes 580, bl. 13B, SP, CEP: 05508-900, São Paulo, Brazil.
Inflamm Res. 2004 Sep;53(9):442-52. doi: 10.1007/s00011-004-1288-7.
Previous studies showed that animals chronically treated with NG-nitro-L-arginine methyl ester (L-NAME) have a reduced inflammatory reaction. Now the role of L-NAME treatment (20 mg/Kg/day/14 days) on leukocyte mobilisation was assessed in rats.
In vivo leukocyte recruitment evoked by Bothrops jararaca venom (BjV) and nitrite/nitrate (NO2-/NO3-; Griess reaction) were evaluated in the air pouch cavity. Haematological parameters were evaluated in the bone marrow and in the peripheral compartment. Microcirculatory blood flow, number of rolling and adhered leukocytes, vascular reactivity and mast cell activity were studied by intravital microscopy. Blood pressure was measured by the tail-cuff method. L-selectin and beta(2) integrin expressions on peripheral and bone marrow leukocytes were quantified by flow cytometry.
When compared with control rats (D-NAME) L-NAME treated rats had reduced PMN cell infiltrate (50%) and NO2-/NO3- (27%) in the air pouch cavity. Rolling leukocytes were decreased (70%) in L-NAME-treated animals, which was reversed by topical application of NO donor (SIN-1). BjV stimulation increased the number of rolling and adhered leukocytes only in control rats. Systemic blood pressure, microcirculatory blood flow and microvascular reactivity was not altered by the treatment. Only the vessel response to acetylcholine was delayed in treated rats. Peripheral PMN cells were increased by L-NAME treatment (100%), but the number of bone marrow cells was not altered. The treatment reduced L-selectin expression on circulating leukocytes, by either with (16%) or without (26%) stimulation with BjV; PMN cells were more affected (32-37%). Impairment of L-selectin expression was also verified in bone marrow cells under stimulation with BjV.
Results show that this schedule of L-NAME treatment promotes a decrease on L-selectin expression. This effect may promote the standstill of leukocytes in the blood compartment and may be responsible, at least in part, for the observed deficient leukocyte-endothelium interactions with subsequent impairment of leukocyte migration to the inflammatory site.
先前的研究表明，长期用NG-硝基-L-精氨酸甲酯（L-NAME）处理的动物炎症反应减弱。现在评估了L-NAME处理（20毫克/千克/天/14天）对大鼠白细胞动员的作用。
在气袋腔中评估了巴西矛头蝮蛇毒（BjV）和亚硝酸盐/硝酸盐（NO2-/NO3-；格里斯反应）诱发的体内白细胞募集。在骨髓和外周血中评估血液学参数。通过活体显微镜研究微循环血流量、滚动和黏附白细胞数量、血管反应性和肥大细胞活性。用尾套法测量血压。通过流式细胞术定量外周血和骨髓白细胞上的L-选择素和β2整合素表达。
与对照大鼠（D-NAME）相比，L-NAME处理的大鼠气袋腔中的PMN细胞浸润减少（50%），NO2-/NO3-减少（27%）。L-NAME处理的动物中滚动白细胞减少（70%），局部应用NO供体（SIN-1）可使其恢复。BjV刺激仅在对照大鼠中增加了滚动和黏附白细胞的数量。治疗未改变全身血压、微循环血流量和微血管反应性。仅治疗大鼠对乙酰胆碱的血管反应延迟。L-NAME处理使外周PMN细胞增加（100%），但骨髓细胞数量未改变。该处理降低了循环白细胞上L-选择素的表达，无论是否用BjV刺激（有刺激时降低16%，无刺激时降低26%）；PMN细胞受影响更大（降低32%-37%）。在BjV刺激下，骨髓细胞中也证实了L-选择素表达受损。
结果表明，这种L-NAME处理方案可促进L-选择素表达降低。这种作用可能促进白细胞在血管内停滞，并且可能至少部分地导致观察到的白细胞-内皮相互作用缺陷以及随后白细胞向炎症部位迁移受损。
