15.2. Physiological and pathological observations on rat middle cerebral arteries and human AVM tissue cultures following single high-dose gamma irradiation

O. Major, G. Szeifert, A. Kemeny

Research output: Chapter in Book/Report/Conference proceedingChapter

3 Citations (Scopus)

Abstract

In vitro isometric myograph and histopathological studies were performed on rat middle cerebral arteries (MCAs) to explore changes in contractile capacity following experimental Gamma Knife radiosurgery. Right MCAs were treated with 25 Gy and 50 Gy at the 50% isodose line, while contralateral vessels received 15 Gy and 20 Gy at the 20% isodose region. Survival period varied from 3 to 18 months. Reduction in contractile capacity of irradiated normal rat MCAs was detected but their lumina remained patent. In another study, we investigated human AVM tissue cultures in order to detect genetic and phenotypic modifications contributing to vessel occlusion after irradiation. In culture, the proliferation index decreased considerably following 15-, 20-, 25- or 50-Gy irradiation at the 5th posttreatment day and remained depressed during the observation period of 14 days. P53, p21Waf-1 and mdm-2 mRNA contents were elevated significantly after irradiation, indicating enhanced apoptosis. Immunohistochemistry revealed vigorous vimentin positivity in the nonirradiated control AVM cultures, which gradually decreased by the time in the irradiated specimens. Smooth muscle α-actin positivity was prominent in the irradiated cultivated samples, suggesting transformation of resting fibroblasts onto activated myofibroblastic elements with contractile capacity. This transformation process was confirmed by the appearance of TGF-β in the irradiated AVM cell lines also. These data support the hypothesis that one of the contributing factors to AVM shrinkage and obliteration after radiosurgery might be fibrocyte-myofibroblastic cell transformation in the vessel wall.

Original languageEnglish
Title of host publicationRadiosurgery and Pathological Fundamentals
EditorsGyorgy Szeifert, Marc Levivier, Douglas Kondziolka, Dade Lunsford
Pages375-387
Number of pages13
DOIs
Publication statusPublished - Dec 1 2007

Publication series

NameProgress in Neurological Surgery
Volume20
ISSN (Print)0079-6492
ISSN (Electronic)1662-3924

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ASJC Scopus subject areas

  • Surgery
  • Clinical Neurology

Cite this

Major, O., Szeifert, G., & Kemeny, A. (2007). 15.2. Physiological and pathological observations on rat middle cerebral arteries and human AVM tissue cultures following single high-dose gamma irradiation. In G. Szeifert, M. Levivier, D. Kondziolka, & D. Lunsford (Eds.), Radiosurgery and Pathological Fundamentals (pp. 375-387). (Progress in Neurological Surgery; Vol. 20). https://doi.org/10.1159/000100179