ULTRASTRUCTURAL FINDINGS IN THE ZONA FASCICULATA OF THE ADRENAL CORTEX IN ANIMALS EXPOSED TO A SINGLE HIGH DOSE OF GENERAL OR LOCAL RADIATION (in Italian)
Electron microscopic observations were made of this adrenocortical zone of male adult rats irradiated with 200kv x rays. Irradiation was given at a rate of 90 r/min to a total dose of 1000 r, either to the entire body or to a 4 x6 lumbar region over the adrenals. At the earliest time examined, one day postirradiation, the mitochondrial membrane was disrupted and the number of cristae reduced; the nuclear membrane was detached. In contrast to these changes in the zona fasciculata, none were found at this time in the zona glomerulosa. After three days, greater changes were noted in the zona fasciculata: the mitochondria were completely devoid of cristae and were filled with granular material; the endoplasmic reticulum was enormously dilated and vacuolated, some vacuoles appearing as large as mitochondria. Extravasated erythrocytes indicated extensive local, small hemorrhages. After seven days the changes were less marked, some repair of mitochondria was evident and endoplasmic reticulum was less dilated. Ribosomes free in the cytoplasm were noted and defects in the nuclear membrane persisted. The above changes, described as seen in whole-body irradiated rats, were also found after local irradiation, but in the latter case the changes seen at one day resembled those seen at three days in panirradiated rats. The results demonstrated the considerably greater radiosensitivity of the zona fasciculata as compared with the zona glomerulosa, in which little or no chaage was evident. Since injection of ACTH in rats produces marked changes in mitochondria of the zona fasciculata, resembling those seen here, it is suggested that the stress reaction, induced by irradiation, and the consequent stimulation of hypophyseal ACTH secretion may have been responsible for most of the observed changes, at least in the mitochondrion. The stress reaction appeared to be stimulated by local as well as by whole-body irradiation. (BBB)
- Research Organization:
- Universita, Milan
- NSA Number:
- NSA-17-038774
- OSTI ID:
- 4634684
- Journal Information:
- Atti Accad. Med. Lombarda, Journal Name: Atti Accad. Med. Lombarda Vol. Vol: 17
- Country of Publication:
- Country unknown/Code not available
- Language:
- Italian
Similar Records
ELECTRON MICROSCOPIC STUDY OF CHANGES IN LIVER CELLS AFTER COMBINED TREATMENT WITH CARBON TETRACHLORIDE AND X RAYS
ELECTRON MICROSCOPIC OBSERVATIONS ON THE LUNG IN IRRADIATED ANIMALS