Abstract In contrast to the well-known reaction of hypochlorous acid with hydrogen peroxide, no singlet oxygen is formed as the result of reaction between hypochlorous acid and tert -butyl hydroperoxide. The reaction with hydrogen peroxide yielded a quadratic dependence of light intensity on reactant concentration, a drastic enhancement of luminescence yield using D 2 O as solvent and only an emission of red light, that are typical characteristics of emission resulting from two molecules of delta singlet oxygen. Other chemiluminescence properties were observed using tert-butyl hydroperoxide. There was a linear dependence of light intensity on reactant concentration using rm-butyl hydroperoxide in excess with a decline of emission at higher concentrations. 1 H-NMR spectroscopic analysis revealed di-tert-butyl peroxide, tert -butanol and also tert-butyl hypochlorite, acetone and acetate as products of the reaction between hypochlorous acid and tert -butyl hydroperoxide. The formation of di-tert-butyl peroxide is only possible assuming a tert-butyloxy radical as primary intermediate product of this reaction. Our results demonstrate that alkoxy radicals derived from organic hydroperoxides can participate in lipid peroxidation induced by hypochlorous acid. On the other hand, singlet oxygen did not influence the yield of peroxidation products. Changing H 2 O for D 2 O in suspension of egg yolk phosphaditylcholine no differences in accumulation of thiobarbituric acid reactive products were observed.
Sulfation of glycosaminoglycans (GAGs) of components of extracellular matrix and cell surface is an important regulatory mechanism in inflammatory immune response. All sulfotransferases use 3′-phosphoadenosine 5′-phosphosulfate (PAPS) as a common sulfate donor that is produced by PAPS synthase.
Polymorphonuclear leukocytes (neutrophils) release a variety of toxic agents--proteins and reactive oxygen species (ROS)--that are used to inactivate foreign microorganisms in the non-specific immune response. This study was undertaken to compare intracellular signalling pathways that lead to the ROS production as well as degranulation of azurophilic granules of human fMet-Leu-Phe/cytochalasin B stimulated neutrophils.Luminol-amplified chemiluminescence was used for monitoring the oxidative activity of human neutrophils in the presence of various inhibitors. The elastase activity was assessed in the neutrophil supernatant as a marker for degranulation of azurophilic granules.Tested inhibitors of enzymes of signalling cascades showed the same effect on the ROS production and on the activity of elastase released from neutrophils. The only difference was obtained with staurosporine: it inhibited the chemiluminescence response, but increased the elastase release.Early signalling pathways leading to the ROS production and the degranulation are ubiquitous in human neutrophils. They are branching most probably at the point of the phosphatidic acid production by phospholipase D. A protein kinase activated by this lipid second messenger might play a central regulatory role in human neutrophils.
