Beiträge zur Morphologie und Physiologie des Lymphgewebes

Hoepke, Hermann

doi:10.1007/bf02118253

Cited by 31 publications

(5 citation statements)

References 18 publications

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“…No conclusion has been drawn as to whether the nature of splenic hemopoiesis in the musk shrew is primary or secondary. The active hemopoiesis in the spleen of Insectivora (Hoepke, 1933;Tanaka, 1986a) may be a physiological activity in this particular mammalian group which relates to thLeir persistent primitive vascular architecture.…”

Section: Discussionmentioning

confidence: 99%

“…A similar event is believed to occur in higher vertebrates, and the spleen is no longer the primary hemopoietic organ in most of the higher mammals (Bloom and Fawcett, 1975). A significant level of hemopoiesis, more active than the extramedullary hemopoiesis that occurs in the rodent spleen, has been noted in the spleen of insectivores (the hedgehog, mole, musk shrew) (Hoepke, 1933;Snook, 1950;Fukuta et al, 1982;Tanaka, 1986a). The spleen of the musk shrew (and probably other species of insectivores) differs structurally from the spleen of most mammals in that the intermediate zone which is composed of plexiform venules (or venous capillaries) is located between the white and red pulp (Tanaka, 1986a).…”

Section: Introductionmentioning

confidence: 99%

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Splenic hemopoiesis of the platypus (Ornithorhynchus anatinus): Evidence of primary hemopoiesis in the spleen of a primitive mammal

1988

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The generation of blood cells has been observed in the spleen and in the bone marrow of the platypus. Hemopoiesis was found to be far more active in the spleen than in the bone marrow judging by the number of proliferating hemopoietic elements within a unit area of tissue from each organ. Granulocytes, erythroblasts, and megakaryocytes, with the related immature forms for each cell line, were noted in the spleen. In contrast, there were very few examples of immature forms of these cell lines and a complete absence of mature megakaryocytes in the bone marrow. These findings suggest that the spleen is the primary hemopoietic organ in the platypus. Since the platypus is one of two species representing the most primitive existing mammals, it seems likely that the spleen may be the primary hemopoietic organ in mammalian evolution.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Splenic hemopoiesis of the platypus (Ornithorhynchus anatinus): Evidence of primary hemopoiesis in the spleen of a primitive mammal

1988

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“…A similar tissue layer was later found in the mole (Insectivora) spleen and is interpreted to be the IZ (Tanaka, 1987). A clear tissue zone around the lymphatic tissue in the hedgehog (Insectivora) spleen has also been noted (Hoepke, 1933); this zone is probably the IZ. These observations suggest that the IZ may be a common morphological characteristic of the insectivore spleen.…”

Section: Introductionmentioning

confidence: 94%

“…Naturally, no specific comment about this structure was made by these authors. Hoepke (1933) studied the arterial terminal of the hedgehog (Erinaceus europaeus) spleen in and around the white pulp by reconstruction of serial sections in nonperfused spleens and concluded that the arterial terminal ends definitively open in areas around the white pulp. Snook (1950) studied the intrasplenic vascular channel of several mammalian species, including the mole.…”

Section: Structure Of the Insectivore Spleenmentioning

confidence: 99%

“Intermediate zone” of mammalian spleens: Light and electron microscopic study of three primitive mammalian species (platypus, shrew, and mole) with special reference to intrasplenic arteriovenous communication

Tanaka

1990

Am. J. Anat.

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The intermediate zone (IZ) of nonperfused and perfused spleens in three species of primitive mammals (shrew, mole, platypus) was studied morphologically. The IZ is a tissue zone consisting of plexiform vessels, probably venous capillaries, and is located transitionally between the white and red pulp. The IZ is separated from the white pulp by the arterial net (AN), in which the white pulp arteries terminate. Development of the IZ differs between the three species examined being distinctive in the platypus and shrew. The IZ is thin in the mole spleen. A closed type of arteriovenous (A-V) anastomosis was demonstrated in or around the IZ in the two Insectivora species examined. In the shrew spleen, peripheral arterial branches running within the IZ anastomose with the AN around the follicle. The AN anastomoses eventually with venous plexiform vessels of the IZ around the nonfollicular area of the white pulp to form a closed system. In the mole spleen, A-V anastomoses were noted between white pulp arteries (follicular and AN) and veins of the red pulp, either by direct communication or through fenestrated IZ vessels compatible with the plexiform vessels of the shrew spleen. A-V anastomosis in the IZ is probable, but not confirmed, in the platypus spleen, as analysis was limited to a nonperfused specimen. Well-developed ellipsoids were noted around arterial terminals of the IZ in the shrew spleen. Ellipsoids were also noted around all arterial terminals of the mole spleen directed to the red pulp. Most ellipsoids of the mole spleen appeared located within the IZ. No ellipsoids were present around arterial terminals of the IZ in the platypus spleen. Closed circulation was noted in terminals of the pulp artery in spleens of all three species. All pulp arteries of the mole spleen are postellipsoid segments of white pulp (AN and follicle) arteries. No ellipsoids were found around terminals of the pulp artery (penicillar artery) in shrew and platypus spleens. The IZ is probably homologous to the perilymphatic sinusoid (vein) of the lungfish spleen and may be regarded as part of the red pulp. The IZ may be representative of primitive mammalian spleens that have closed circulation. The marginal zone (MZ) of common mammalian spleens is probably a modified IZ by differentiation (remodelling) of the intrasplenic vein. In this process, withdrawal of venous vessels from the IZ occurred, leaving a lymphoreticular zone with open circulation (MZ). The marginal sinus reported in some mammalian spleens is probably a modified AN formed during this process. Possible morphological alterations of the spleen in vertebrate phylogeny are discussed.

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“…Material studied Results macroscopic observa-"Vasa illa non solum in splenis super-F. Ruysch, 1727 W. Tomsa, 1863 E. Kyber, 1872Bannwarth, 1891 M. Katsuki, 1924 H. Hoepke, 1932 E. Jaeger, 1937 T. Snook Two efferent lymphatic systems were traced : perivenous, which originated from the subintimal spaces of veins, and periarterial which started from follicles. Periarterial and paraarterial lymphatics are formed by fine reticular membrane and endothelium.…”

Section: Investigatormentioning

confidence: 99%