Lack of effect of opioid peptides,morphine and naloxone on superoxide formation in human neutrophils and HL-60 leukemic cells

Summary There are controversial reports in the literature concerning the effects of opioids on superoxide (O ₂ ^– ) formation in phagocytes, these agents being either inhibitory or stimulatory. We re-examined this issue and compared the effects of the Chemotactic peptide, N-formyl-l,-methionyl-l-leucyl-l-phenylalanine (fMet-Leu-Phe), phorbol myristate acetate (PMA), ATP, platelet activating factor (PAF), cytochalasin B (CB) and prostaglandin E₁ (PGE₁) with those of various opioids on O ₂ ^– formation in human neutrophils and HL-60 leukemic cells under defined experimental conditions. In the presence of CB, fMet-Leu-Phe and PAF concentration-dependently activated O ₂ ^– formation in neutrophils with EC₅₀ values of 20 nM and 100 nM, respectively. In the absence of CB, fMet-Leu-Phe and PAF were much less effective. PAF synergistically enhanced O ₂ ^– formation induced by fMet-Leu-Phe. ATP at a concentration of 100 M and the opioids, methionine enkephalin, -endorphin, dynorphin, [d-Ala², N-Me-Phe⁴, Gly⁵-ol]-enkephalin, [d-Ala²-d-Leu⁵]-enkephalin and morphine at concentrations between 10 pM to 1 M did not activate O ₂ ^– formation. ATP but not \-endorphin potentiated fMet-Leu-Phe-induced O ₂ ^– formation. O ₂ ^– formation induced by a maximally stimulatory concentration of PMA (100 ng/ml) was enhanced by fMet-Leu-Phe but was unaffected by methionine enkephalin or PGE₁. PMA at a non-stimulatory concentration (2 ng/ml) potentiated the effect of fMet-Leu-Phe but did not induce responsiveness to PAF, ATP or -endorphin. PGE₁ strongly inhibited fMet-Leu-Phe-induced O ₂ ^– formation, whereas morphine, methionine enkephalin and the opioid antagonist, naloxone, were without effect. In HL-60 cells differentiated with dibutyryl cAMP, fMet-Leu-Phe, PAF and ATP but not -endorphin activated O ₂ ^– formation. Our results show that O ₂ ^– formation is differentially regulated by various classes of intercellular signal molecules and that opioids do not play a role in the regulation of O ₂ ^– formation. The precise definition of the experimental conditions and control experiments with established modulators of O ₂ ^– formation are essential to evaluate the role of opioids in the regulation of this effector system.Send offprint requests to R. Seifert at the above address     

Short-term enzyme replacement in the murine model of Sanfilippo syndrome type B

The Sanfilippo syndrome type B (MPS III B) is an autosomal recessive disease caused by deficiency of alpha-N-acetylglucosaminidase (EC 3. 2.1.50), one of the lysosomal enzymes required for the degradation of heparan sulfate. The disease is characterized by profound neurodegeneration but relatively mild somatic manifestations, and is usually fatal in the second decade. A mouse model had been generated by disruption of the Naglu gene in order to facilitate the study of pathogenesis and the development of therapy for this currently untreatable disease. Recombinant human alpha-N-acetylglucosaminidase (rhNAGLU) was prepared from secretions of Lec1 mutant Chinese hamster ovary cells. The enzyme, which has only unphosphorylated high-mannose carbohydrate chains, was endocytosed by mouse peritoneal macrophages via mannose receptors, with half-maximal uptake at ca. 10(-7) M. When administered intravenously to 3 month-old mice, rhNAGLU was taken up avidly by liver and spleen but marginally if at all by thymus, lung, kidney, heart, and brain (in order of diminishing uptake). The half-life of the enzyme was 2.5 days in liver and spleen. Immunohistochemistry and electron microscopy showed that only macrophages were involved in enzyme uptake and correction in these two organs, yet the storage of glycosaminoglycan was reduced to almost normal levels. The results show that the macrophage-targeted rhNAGLU can substantially reduce the body burden of glycosaminoglycan storage in the mouse model of Sanfilippo syndrome III B.     

Study of β‐casein denaturation by microparticle‐enhanced nephelometric immunoassay

Rabbit anti‐native bovine ß‐casein antiserum reacted with native ß‐casein and fragments f( 1–105/7) and f( 106–209) formed during ß‐casein proteolysis by plasmin. Agglutination of ß‐casein‐coated microparticles by anti‐native ß‐casein antiserum was weakly inhibited by ß‐casein f(1–105/7) and ß‐casein f( 106–209) (0·04 and 1·4%, respectively, compared with native ß‐casein). Immunoreactivity of these ß‐casein peptides in microparticle‐enhanced nephelometric immunoassay was more preserved in the whole ß‐casein than in its isolated fragments. The protein concentration producing 50% inhibition of the ß‐casein‐coated microparticle agglutination with anti‐native ß‐casein antiserum increased during ß‐casein denaturation. A microparticle‐enhanced nephelometric immunoassay, quantifying changes of this inhibiting protein concentration, permitted detection of alteration of the immunoreactivity of ß‐casein during its plasmin proteolysis and heat denaturation, providing an adequate test for the integrity of the whole molecule.     

Effect of peptide Pro-Gly-Pro on stress-induced behavioral changes in rats

Tripeptide PGP in a dose of 1 mg/kg had a correcting effect on behavioral disorders in rats induced by stress exposure (forced swimming). PGP prevented the increase in anxiety and decrease in orientation and exploratory activity. Our results suggest that the effect of this peptide is realized via central nervous structures involved in organism’s response to stress factors. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 138, No. 7, pp. 9–11, July, 2004     

Intraduodenal neuropeptide levels,but not plasma levels,vary in a cyclic fashion with the migrating motor complex

The neurohormonal control of the migrating motor complex (MMC) is not fully understood. The hypothesis of the present study was that neuropeptide levels might vary with the different phases of the MMC and that a similar variation might be found in the secretions of the gastrointestinal tract. Thus, plasma and intraduodenal concentrations of vasoactive intestinal peptide (VIP), somatostatin (SOM), substance P (SP) and neurokinin A (NKA) were determined by radioimmunoassay every 10 min during two complete MMC cycles in eight male subjects. For comparison, plasma motilin (MOT) concentrations were measured. Plasma concentrations of MOT (mean peak value ± SEM; 39 ± 6 pmol L^?1), but none of the neuropeptides studied, showed a cyclic variation in plasma with the different phases of the MMC. Peak intraduodenal concentrations of VIP (79 ± 23 pmol L^?1),?SOM (2437 ± 432 pmol L^?1) and SP (718 ± 326 pmol L^?1) occurred at or at the time point before the onset of phase III of the MMC. No such correlation was observed for NKA. These results demonstrate that intraduodenal but not plasma concentrations of the neuropeptides VIP, SOM and SP show an association with phase III of the MMC. The biological relevance of this finding is yet unclear, but the results raise the possibility that gut neuropeptides may regulate fasting motility through a luminal release.     

App17肽防治去卵巢大鼠海马神经细胞的凋亡

目的:观察去卵巢大鼠几种神经元凋亡相关蛋白的表达,并用TUNEL试剂盒检测,研究缺乏雌激素是否引起神经元凋亡;评估App17肽是否能改善去卵巢大鼠的神经细胞凋亡,初步探讨App17肽的神经保护作用机制。方法:雌性Wistar大鼠随机分3组:假手术组(shamcontrol组),卵巢去势对照组(OVX组),App17肽实验组(17P+OVX组)。Sham组做假手术,OVX组和17P+OVX组做双侧卵巢切除术。17P+OVX组从卵巢去势第7周开始用App17肽治疗6周,用免疫组化和Westernblot方法观察AIF、Bax、Bcl-2的表达,用TUNEL法检测凋亡情况。结果:免疫组织化学和Westernblot结果表明App17肽实验组AIF、Bax表达明显少于去卵巢组;Bcl-2在App17肽实验组的表达明显高于去卵巢组。TUNEL结果表明App17肽实验组凋亡细胞明显少于去卵巢组。结论:雌激素缺乏引起去卵巢大鼠海马和皮层神经细胞凋亡相关蛋白改变和出现凋亡细胞,App17肽具有明显的防治作用。     

Biological activity of thymus preparations from sheep of different ages

Research Institute of Epidemiology, Microbiology, and Infectious Diseases, Ministry of Health of the Uzbek SSR. Department of Immunology, Central Research Laboratory, Medical Institute, Tashkent. Research Institute of Physicochemical Medicine, Ministry of Health of the RSFSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR Yu. M. Lopukhin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 105, No. 3, pp. 308–309, March, 1988.