Jesic Snezana, Stojiljkovic Ljuba, Petrovic Zeljko, Djordjevic Vladimir, Nesic Vladimir, Stosic Svetlana
Institute for Otorhinolaryngology and Maxillofacial surgery, Clinical Centre of Serbia, 11000 Belgrade, Pasterova 2 Street, Serbia and Montenegro.
Int J Pediatr Otorhinolaryngol. 2006 Jun;70(6):1069-76. doi: 10.1016/j.ijporl.2005.11.002. Epub 2006 Jan 6.
The role of pharyngeal lymphoid tissue in etiopathogenesis of secretory otitis is not yet defined. The influence of tonsillar and adenoid mass, weight, obstruction of naspharyngeal orrifitium, bacterial reservoire or some immunological events are of scientific interest. Tissue nonspecific alkaline phosphatase (TNAP) and acid phosphatase (ACP) are enzymes detected in lymphoid tissue, TNAP as characteristic of B cells, ACP as a characteristic of macrophages and folucullardentritic cells. These enzymes interfere in cell metabolism by removing 5' phosphate group from nucleotides and proteins. Specific activity and kinetic properties were studied in palatinal tonsils and adenoids of children with secretory otitis (OME) and compared with children with recurrent tonsillitis without ear involvement.
Adenoid and tonsillar tissue of l7 children with OME and 30 children with recurrent tonsillitis were subjected to biochemical investigation using method of releasing of p-nitrophenol from p-nitrophenylphosphate (pNPP). Kinetic parameters as Michaelis-Menten constant were calculated by non-linear regression estimation method.
Specific activity of adenoid alkaline phosphatase was lower in children with OME in relation to children with recurrent tonsillitis (t=5.733507, p<0.01). Specific activity of adenoid acid phosphatase was also lower in children with OME (t=3.655456, p<0.01). pH optimum for both enzymes was the same in these two groups of children. Michaelis-Menten constant for both enzymes was significantly higher in adenoid of children with OME than in children with recurrent tonsillitis suggesting lower enzyme affinity for the substrate.
Differences in specific activities and kinetic properties of adenoid alkaline and acid phosphatases between children with OME and children with recurrent tonsillitis without OME were verified in this study. The results of the study are not able to explain the alteration of alkaline and acid phosphatase characteristics but could point to some possible and specific role of nasopharyngeal lymphoid tissue in pathogenesis of secretary otitis.
咽淋巴组织在分泌性中耳炎发病机制中的作用尚未明确。扁桃体和腺样体的大小、重量、鼻咽口阻塞、细菌储存库或某些免疫事件的影响具有科学研究价值。组织非特异性碱性磷酸酶(TNAP)和酸性磷酸酶(ACP)是在淋巴组织中检测到的酶,TNAP是B细胞的特征酶,ACP是巨噬细胞和滤泡树突状细胞的特征酶。这些酶通过从核苷酸和蛋白质中去除5'磷酸基团来干扰细胞代谢。对分泌性中耳炎(OME)患儿的腭扁桃体和腺样体中的特异性活性和动力学特性进行了研究,并与无耳部受累的复发性扁桃体炎患儿进行了比较。
采用从对硝基苯磷酸酯(pNPP)释放对硝基苯酚的方法,对17例OME患儿和30例复发性扁桃体炎患儿的腺样体和扁桃体组织进行生化研究。通过非线性回归估计法计算米氏常数等动力学参数。
与复发性扁桃体炎患儿相比,OME患儿腺样体碱性磷酸酶的特异性活性较低(t=5.733507,p<0.01)。OME患儿腺样体酸性磷酸酶的特异性活性也较低(t=3.655456,p<0.01)。两组患儿中这两种酶的最适pH值相同。OME患儿腺样体中这两种酶的米氏常数均显著高于复发性扁桃体炎患儿,表明酶对底物的亲和力较低。
本研究证实了OME患儿与无OME的复发性扁桃体炎患儿腺样体碱性和酸性磷酸酶的特异性活性及动力学特性存在差异。该研究结果无法解释碱性和酸性磷酸酶特性的改变,但可能提示鼻咽淋巴组织在分泌性中耳炎发病机制中存在一些可能的特定作用。