【摘要】 <正> 日本血吸虫尾蚴侵入终末宿主体内后,童虫期的迁移途径曾经若干学者的考察,如宫川米次(1912,1913,1916),楢林兵三郎(1914,1916),Miyagawa and Takemoto(1921)Faust and Meleney(924),Sadun,Lin and Williams(1958)等。研究曼氏血吸虫的迁移途径的有 Faust,Jones and Hoffman(1934)。在经肤感染发现后,在本世纪十至二十年代更多还原

【Abstract】 The route of migration of Schistosoma japonicum was intensively studied soon after the discovery by Fujmami and Nakamura (1909) that skin is the principal portal of entry for the eereariae which gain access to the mammalian host. Two schools of parasitologists differed in their opinion as to how the schistosomula reach their definitive site in the portal vessels through the circulatory system or through tissue migration. It is now agreed by most authorities (Miyagawa and Takemoto, 1921; Faust and Meleney, 1924) that the course of migration is as follows: After the larvae enter capillaries or venules of the peripheral circulation, they are carried in the venous blood stream through the heart to the lungs, work their way through the lung capillaries, then are carried by the arterial blood stream to the mesenteric capillaries from which they work again to enter the portal system. The course of migration as stated above has been thus recorded in textbooks of parasitology. Since the structure of the mammalian circulatory system is so complex and since the migratory course which consists of following blood stream passively and of active movements while encountering the capillary barriers, the whole process of migration, although known in its essentials, remains to be elucidated in detail. We took up the study employing somewhat different methods from those of former workers, by tying large vessels and drawing blood with syringe for the examination of schistosomula. Mice and rabbits were used as experimental animals. "We also adopted massive invasion of cercariae, a method used by recent investigators in experimental schistosomiasis (Yolles et al, 1949; Hewitt and Gill. 1960; Grimaldo and Kershaw, 1960). In general, our results confirmed the conclusion arrived at by former investigators in that the principal route of migration is by the blood stream and that, the worms made their way out from the lung tissue into the pleural cavity and traversed the mediastinum or the diaphram into the peritoneal cavity is only an accidental or accessory course. The earliest time for schistosomula to appear in the lung is 24 hours. They continue to arrive in this organ for 3 or 4 days. Schistosomula arrive in the portal vein in 3 and half days, but they may be delayed as late as 6 days. During 4 to 13 days after invasion, schistosomula in the portal vein greatly outnumber those in the mesen-teric veins, indicating that they first arrived that portion of portal vein close to the liver, where they grow to premature stage and then migrate against the blood stream to the mesenteric veins.Petechial hemorrhages appeared on various organs such as lungs, stomach, intestine, kidneys, etc. Their first appearance and the time of continuing to occur were recorded. The lungs were the organs which suffered most intensely. The hemorrhages first appeared ,on the 2nd or 3rd day after invasion. The number increased to its peak on the 4th or 5th day. In one rabbit infected with 4,000 cercariae, as many as 1.071 hemorrhagic spots were found on the surface of its lungs. Judging from our observations, it can be deduced that the majority of the schistosomula invading the cutaneous tissue must have arrived to the lungs on the 3rd or 4th day. Although numerous spots still persisted on the 5th or 6th day, they must be the remains of the previous days, as by dissection it was found that the number of schistosomula in the alveolar wall already began to decrease on the 5th day. On the 7th day some of the spots began to fade away. On the 3rd or 4th day after invasion, schistosomula were not only found in the right heart and pulmonary arteries but were also found in the pulmonary veins, aortic arches and dorsal aorta. These findings suggest that after arriving the lungs the larvae were immediately carried by the systemic circulation.The petechial hemorrhages on the stomach appeared first on the 3rd day and those on the intestine somewhat later. The hemorrhagic spots on the stomach wall were observed to lie beneath the gastric mucosa and were also visible from the peritoneal更多还原