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Ionizing Radiation Enhances Activity of Angiotensin-Converting Enzyme in Rat Aorta
A F Korystova1, L N Kublik1, M Kh Levitman1
1Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
Bulletin of Experimental Biology and Medicine
|June 21, 2018
Summary
Radiation exposure increases angiotensin-converting enzyme activity in rat aorta, peaking early after whole-body irradiation. This effect is linked to monocyte adhesion, which decreases with higher radiation doses.
Area of Science:
- Radiology
- Cardiovascular Biology
- Cell Biology
Background:
- Radiotherapy involves ionizing radiation, which can impact physiological processes.
- Angiotensin-converting enzyme (ACE) plays a role in cardiovascular regulation.
- Early effects of radiation on vascular enzyme activity are not fully understood.
Purpose of the Study:
- To investigate changes in angiotensin-converting enzyme activity in rat aorta following irradiation.
- To determine the relationship between radiation dose, irradiation type (whole-body vs. local), and ACE activity.
- To explore the role of monocyte adhesion in radiation-induced ACE activity changes.
Main Methods:
- Male Wistar rats were subjected to whole-body or local X-ray irradiation (1-7.5 Gy).
- Angiotensin-converting enzyme activity was measured in aorta segments using hippuryl-histidine-leucine hydrolysis.
- Monocyte adhesion to plastic was assessed after irradiation.
Main Results:
- Whole-body irradiation (2.5 Gy) increased ACE activity, peaking at 2 hours post-exposure.
- Local irradiation also increased ACE activity transiently (2 hours).
- Higher whole-body doses (>2.5 Gy) showed a diminished ACE activity increase, while local irradiation effects were dose-independent; monocyte adhesion decreased with increasing whole-body dose.
Conclusions:
- Radiation-induced increase in aortic ACE activity is associated with monocyte adhesion to the endothelium.
- Higher radiation doses may impair this effect due to radiation damage to monocytes.
- Findings suggest a link between radiation, monocytes, and vascular ACE activity.
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