Endothelial Cell Proliferation in the Rat Heart Following Local Heart Irradiation
- 1 January 1990
- journal article
- research article
- Published by Taylor & Francis in International Journal of Radiation Biology
- Vol. 57 (5), 1017-1030
- https://doi.org/10.1080/09553009014551131
Abstract
Radiation-induced myocardial degeneration in the rat is preceded by changes in capillary structure and function, which may be a major factor in the pathogenesis of radiation-induced heart disease. In order to investigate the mechanism of capillary damage we studied endothelial cell proliferation in untreated control rats and in rats at different times following local heart irradiation with 20 Gy using [3H]thymidine autoradiography. Since the latency times of myocardial degeneration as well as capillary damage are about twice as long in Sprague-Dawley rats as in Wistar rats, endothelial cell proliferation was studied in both strains. The percentage of labelled nuclei (LI) after repeated labelling over a period of 12 h was 0·32 ± 0·06 in control animals of both strains. Therefore the turnover time of endothelial cells was estimated to be between 115 and 400 days. Following irradiation the LI increased above control levels. In both strains this was concurrent with the time of onset of capillary depletion and alkaline phosphatase loss, which occurred at around 23 days post-irradiation in Wistar rats and 58–74 days in Sprague-Dawley rats. In both strains the increase in LI was confined to alkaline-phosphatase-negative areas. In phosphatase-positive areas endothelial cell proliferation was unchanged in spite of the reduction in capillary density. Since, in general, the latency to post-irradiation death of a cell is closely related to its normal turnover time, the decrease in capillary density is not due to mitotic death of proliferating cells as is commonly seen in other tissues.This publication has 21 references indexed in Scilit:
- Capillary endothelial cells express basic fibroblast growth factor, a mitogen that promotes their own growthNature, 1987
- Cardiac ventricular ?2-adrenoceptors in guinea-pigs and rats are localized on the coronary endotheliumNaunyn-Schmiedebergs Archiv für experimentelle Pathologie und Pharmakologie, 1986
- Postoperative radiotherapy in breast cancer—long-term results from the Oslo studyInternational Journal of Radiation Oncology*Biology*Physics, 1986
- Strain differences in the radiation response of the rat heartRadiotherapy and Oncology, 1986
- Radiation-induced heart disease in ratsInternational Journal of Radiation Oncology*Biology*Physics, 1985
- Endothelial proliferation in tumours and normal tissues: Continuous labelling studiesBritish Journal of Cancer, 1984
- Dipyridamole-induced capillary endothelial cell proliferation in the rat heart--a morphometric investigationCardiovascular Research, 1983
- Detection of radiation cardiomyopathy by gated radionuclide angiographyAmerican Journal Of Medicine, 1983
- Myocardial morphology in spontaneously hypertensive and aortic‐constricted ratsJournal of Anatomy, 1978
- Autoradiographic investigations of glial proliferation in the brain of adult mice. II. Cycle time and mode of proliferation of neuroglia and endothelial cellsJournal of Comparative Neurology, 1975