1993 Fiscal Year Final Research Report Summary
Tumor vascular system -scanning electron microscopic observation of resin casts-
| Project/Area Number |
03660316
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
基礎獣医学
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| Research Institution | Azabu University |
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Principal Investigator |
NINOMIYA Hiroyoshi School of Vet.Mod., Azabu University Professor, 獣医学部, 教授 (00063967)
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| Co-Investigator(Kenkyū-buntansha) |
OGIHARA School of Enviro.Hgg.Assistant Prof., 環境保健学部, 講師 (50154381)
TSUCHIYA Hiroyoshi School of Enviro.Hgg.Professor, 環境保健学部, 教授 (60063947)
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| Project Period (FY) |
1991 – 1993
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| Keywords | rat fibrosarcoma / resin casts / SEM / vasculature / mammary tumor / degeneration / intra-arterial cushion / vascular wall |
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| Research Abstract |
A detailed knowledge of the vascular system of tumors is requisite to a clear understanding of tumor physiology and pathology. Accordingly, in this study, examination was made of the vascular architecture of rat fibrosarcomas induced by 3-methyl choranthrene by scanning electron microscopy of resin casts to observe the three-dimensional vascular pattern of the sarcoma. The results were compared with those of corresponding serial sections of India ink-injected tissue. The major arteries in and around tumors appeared devoid of intra-arterial cushions which regulate blood flow. The arterial lining of resin casts was smooth just at the site where it entered the tumor. This may possibly be indication of degeneration and loss of the smooth muscle layr in the vascular wall. Casts of capillaries were very thin from 4 to 6 mum in diameter and very few sprouts could be seen. Capillaries, frequently present in superficial regions of the tumor, formed a rich irregular fine polygonal network. In fi
… More
brous tissue in deeper regions of the tumor, this network was coarse. The absence of intra-arterial cushions and degeneration of muscle cells may thus possibly be the reason for the characteristic haemodynamics of tumors.
ABSTRACT.Scanning electron microscopy of resin casts was carried out on the vascular system of hepatoma in Chinese hamster. Casts of capillaries in the hepatoma were thin and fragmentary and formed a fine randomly arranged network in contrast to those in the liver with radial arrangement and central veins in centrilobular regions. Capillaries in the cancer merged into superficial venules corresponding to central veins while those in the border region merged into sinusoids of adjacent liver tissue. The superficial venules connected to tributaries of hepatic veins to drain into the posterior vena cava. Neovascularization did not occur by sprouting and anastomosing to form hair-pin loops of capillaries but by division of pre-existing vessels into smaller vessels, thus increasing the number of capillaries. The hepatic artery feeding the cancer was seemingly intact. There was no indication of arterio-portal shunts in the hepatoma. KEY WORDS : hepatoma.microvasculature.resin cast. Less
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