ISSN:
0002-9106
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
Orthotopic cardiac allotransplantation was performed on ten adult mongrel dogs. At the time of acute rejection (decline in QRS voltage to at least onehalf of the post-operative level) a cardiac biopsy was removed from the left ventricle of each dog and followed by 300 r of local x-irradiation on five consecutive days. After a full course of x-irradiation (1500r) to each dog a second biopsy was removed from the left ventricle. In this way, each dog acted as its own control in order to determine the effects of x-irradiation on cardiac transplants and the rejection phenomenon. The electron microscopic findings at the time of acute rejection involved primarily the myocytes and their cellular organelles in that the A, I, and Z bands were less distinct and there was significant enlargement and cytological distortion of the mitochondria, endoplasmic reticulum and T tubules. Endothelial hyperplasia of the smaller blood vessels was also more apparent in the pre-irradiation biopsies. Following irradiation the ultrastructural changes appeared to be reversed in six of the ten dogs; mitochondria and other organelles of the myocytes were more normal and the banding of the fibers was more distinct. Vascular alterations were less and the tissue approached normal cytological architecture. Pre- and post-irradiated cardiac tissues were not different in two animals and in two other animals the post-irradiated tissues appeared more abnormal than those showing acute rejection. Local irradiation as a method of immunosuppression in cardiac transplants is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/aja.1001290204
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