Yu P W, Czuprynski C J
Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, WI 53706, USA.
Vet Immunol Immunopathol. 1996 Mar;50(1-2):29-42. doi: 10.1016/0165-2427(95)05485-5.
The purpose of this study was to elucidate likely signal transduction pathways in activated bovine neutrophils, by comparing the effects of various inhibitors on the bovine neutrophil respiratory burst and degranulation in vitro. The protein kinase C(PKC) inhibitors staurosporine, and chelerythine, and the beta-adrenergic receptor antagonist DL-propranolol, markedly inhibited opsonized zymosan (OZ) stimulated luminol-dependent chemiluminescence (LDCL). The G-protein inhibitor pertussis toxin (PT), the protein tyrosine inhibitor genistein, and the calcium channel blocker verapamil also reduced LDCL in a dose-dependent manner. In contrast, the lipoxygenase inhibitor zileuton had only a slight effect, and the cyclooxygenase inhibitor indomethacin had no effect on LDCL. The effects of these inhibitors on degranulation was also examined. Staurosporine, propranolol, and pertussis toxin significantly decreased primary granule (beta-glucosaminidase) release in response to OZ. These inhibitors also significantly reduced both phorbol myristate acetate (PMA)-induced primary and secondary granule (lactoferrin) release. Regulation of secondary granule (lactoferrin) release was complex, as it was significantly depressed by propranolol, enhanced by PT and unaffected by staurosporine. These findings suggest that PKC, beta-adrenergic receptors, G-proteins, protein tyrosine kinase(s) and Ca(2+) uptake, may all be involved in some part of the process of bovine neutrophil activation. Moreover, stimulation of LDCL and degranulation may be mediated through distinct signal transduction pathways.
本研究的目的是通过比较各种抑制剂对体外培养的牛中性粒细胞呼吸爆发和脱颗粒的影响，阐明活化的牛中性粒细胞中可能的信号转导途径。蛋白激酶C（PKC）抑制剂星形孢菌素和白屈菜红碱，以及β-肾上腺素能受体拮抗剂DL-普萘洛尔，均显著抑制调理酵母聚糖（OZ）刺激的鲁米诺依赖性化学发光（LDCL）。G蛋白抑制剂百日咳毒素（PT）、蛋白酪氨酸抑制剂染料木黄酮和钙通道阻滞剂维拉帕米也以剂量依赖性方式降低LDCL。相比之下，脂氧合酶抑制剂齐留通的作用轻微，环氧化酶抑制剂吲哚美辛对LDCL无影响。还研究了这些抑制剂对脱颗粒的影响。星形孢菌素、普萘洛尔和百日咳毒素显著降低了OZ刺激引起的初级颗粒（β-葡萄糖苷酶）释放。这些抑制剂还显著降低了佛波酯（PMA）诱导的初级和次级颗粒（乳铁蛋白）释放。次级颗粒（乳铁蛋白）释放的调节较为复杂，因为它被普萘洛尔显著抑制，被PT增强，而不受星形孢菌素影响。这些发现表明，PKC、β-肾上腺素能受体、G蛋白、蛋白酪氨酸激酶和Ca(2+)摄取可能都参与了牛中性粒细胞活化过程的某些环节。此外，LDCL的刺激和脱颗粒可能通过不同的信号转导途径介导。
