Studies on control of ciliary activity in triton-extracted models of schistosome miracidia

本研究旨在探讨S对血吸虫毛虫表面纤毛活性的控制机制。以曼氏血吸虫卵壳内孵化出的毛虫和毛虫为研究对象，扫描电子显微镜观察发现，毛虫体内覆盖着大量的纤毛，有3种不同的纤毛，主要纤毛长8.5微米，宽0.25微米，分布于除前端外的表面，在氯化钠、氯化钾和蔗糖溶液中测定毛虫的游泳速度。毛虫的游动速度与氯化钠、氯化钾和蔗糖的浓度有关。这些结果表明，纤毛的搏动频率取决于渗透压。在Triton提取模型中，研究了外用试剂对纤毛活动的控制。提取和复活液用于Triton提取的精子模型(Gibbons and Gibbons，1982)，用于血吸虫毛虫。有趣的是，纤毛的跳动频率是氯化钠浓度的函数。纤毛的跳动频率还取决于ATP和镁离子的浓度以及介质的pH值。在标准复活介质(4 mM三磷酸腺苷，1 mM硫酸镁，pH 8.1)中，模型以活毛虫在水中游泳速度的1/3(2m/s)游泳。Ca++对纤毛搏动有部分激活作用，但不引起纤毛搏动的反向。其他二价阳离子不能激活纤毛搏动。VO_3抑制纤毛搏动，Ca~(++)离子载体和佛波醇酯激活卵壳内毛虫的纤毛搏动。W-7、H-7和钙通道阻滞剂可抑制被包裹在蛋壳内的毛虫的纤毛跳动。纤毛活动控制机制的药理研究正在进行中。

The study was designed to explore the mechanism(s) of control of activity of cilia which are present all over the surface of schistosome miracidia. The hatched miracidia and miracidia enclosed within the eggshell of Schistosoma mansoni were used in this study.Scanning electron microscopy revealed that the body is covered with numerous cilia, 3 different cilia are present, and the major cilia are 8.5 mum in length and 0.25 mum in width, which distribute all over the surface except the anterior tip of the body.The swimming speed of miracidia was measured in NaCl, KCl and sucrase solution. The swimming speed of miracidia is a function of the concentration of NaCl, KCl and suorose. These results indicate that beating frequency of miracidial cilia is depend on the osmotic presure.Control of ciliary activities by exterally applied reagents was studied in triton-extracted model. The extraction and reactivating solution used for triton-extracted model of sperm(Gibbons and Gibbons, 1982)was used for schistosome miracidia. Interestingly enough the beating frequency of cilia is function of NaCl concentation. The beating frequency of cilia is also depend on ATP and Mg++ concentration and pH of medium. In a standard reactivating medium (4mM ATP,lmM MgSO4, pH8.1), the models swim at 1/3 of swimming speed of the live miracidia in water(2m/sec). Ca++ activated partially the ciliary beating, but did not cause the reversed direction of beating. Other divalent cations did not activate the ciliary beating. VO3 caused the inhibition of ciliary beating.Ca++ ionophore and phorbol esters activated the cilial beating of miracidia enclosed within the eggshell. W-7, H-7 and calcium channel blocker inhibited the cilial beating of miracidia enclosed within the eggshell.Pharmacological studies on control mechanism of ciliary activities is now in progress.