Histological Study of Spine on Effect of Roentgen Rays in Growing Rabbits

Byun, Young Soo

Abstract

It is well known that effect of roentgen rays upon skeletal system in human and animal causes those following pathologic changes, such as, osteitis, bony necrosis, pathological fracture, alteration of growth and malignant tumor etc. Recently the clinical application of roentgen rays are gradually increased for the purpose of diagnosis and treatment in various spinal disorders. Many investigators, for a long period, since Perthes attracted his studies toward bony dysplasia due to effect of roentgen rays in 1903, reported the effects of roentgen ray upon skeletal system. Tribondeau and Recamier reported the first microscopic study of irradiated bone, and concluded that roentgen ray caused stunting of growth but that no histological changes were demonstrated. It is difficult to find out the literature of histological study of growing bone, but except for the studies of Hinkel, Barr and associated in 1943 and particularly, as far as authors knowledge is concerned, there is few report concerning the effect of roentgen rays upon growing spine. Author interested in the effect of roentgen rays upon growing spine, especially vertebral diaphyseal plate, disc and bone marrow, and had an experimentation of effect on roentgen rays upon the growing spines in fourty immature rabbits. Fourty immature rabbits, age ranged between 4 to 8 weeks and weighted between 500 to 700gm. and fed by the routine animal diet. All rabbits were equally divided into 4 groups; Group 1, Group 2, Group 3 and Group 4. Those rabbits except normal control Goup 1 were irradiated by roentgen ray respectively by various single of 500 R(air), 1000 R, and 3000 R, under condition of 100 K.V.P., 10 M.A., 0.5 mm. copper plus 1.0 mm. alminium filter, 25 cm. distance, and the irradiated time was calculated by 120 R/min, Roengen rays focused on the 12th thoracic vertebral disc, including it's proximal and distal vertebral bodies, and the remaining area were shieled by lead plate with 5.0mm. in thickness and covered by non-radio infiltrable sand bag surrounding the bilateral sides of body, in order not to be exposured by roentgen rays. The method and doses of roentgen rays were followings, such as for Group 2; 6 times of a single of 500R, each radiated by every 3-4th days, Group 3; 3 times of single dose of 1000R each radiated weekly and Group 4; a single dose of 3000R radiated at once. The irradiated rabbits were sacrificed after one month from the day of the last irradiation, and all specimens of 12th thoracic disc and it's neighboured vertebral bodies were removed from the spine and decalcified in nitric acid fixed in paraffin and stained by hematoxylin-eosin. The histological findings of specimen were observed in 3 areas of the vertebral diaphyseal plate, bone marrow and disc and following conclusion were obtained in each area through all groups. 1. Vertebral diaphyseal plate; Columnar disarrangement and the formation of bony plate in the subchondral area were main findings. A) Columnar disarrangement of the group 3 and 4 were worse than Group 2, but no difference between Group 3 and 4. B) The bony plate in the subchondral area of Group 3 and 4 revealed more like acellular with irregular cement lines like mosaic formation. C) The severity of subchondral bony formation revealed no difference among all irradiated 3 groups. (Group 2, 3 and 4) 2. Vertebral body; Decreased hematopoietic cells, extravasation of red bood cells and fibrosis in marrow were main findings. A) The diminished hematopoietic cells were proportionally increased relating to a single dose of roentgen ray. B) The severity of extravasation of red blood cells were not related to a single dose of roentgen ray. C) Myelofibrosis were proportionally changed to increased single dose of roentgen ray. 3. No particular findings of disc were observed among irradiated groups except minor change of hyperchromacity, pyknosis of notochordal cells and expansivility of nucleus pulposus.

Histological Study of Spine on Effect of Roentgen Rays in Growing Rabbits

Abstract

MeSH Terms

Cited

Save citations to file

Email citations