Effect of Ionizing Radiation on Physiological Function in the Anesthetized Rat
Abstract
Exposure of pentobarbital-anesthetized rats to 14.5 MeV electrons results in radiation-induced physiological dysfunction. Responses include transient hypotension, a transient decrease in heart rate, respiratory dysrhythmias, and a prolonged increase in pulse pressure. Magnitudes of these responses are dose-related, and maximal responses can be elicited by either whole- or partial-body (head or abdominal) exposure to 10,000 rad. These responses were associated with a fivefold increase in arterial plasma concentration of epinephrine, whereas histamine, norepinephrine, and B-endorphin did not change during the first minute after the onset of exposure. Administration of diphenhydramine, a histamine receptor antagonist, resulted in a significant decline of baseline cardiovascular function and inhibited radiation-induced cardiovascular dysfunction. The diphenhydramine-induced decrease in preexposure blood pressure was reversed by angiotensin infusion, but this procedure failed to restore the mechanism(s) responsible for the cardiovascular responses to radiation. Results of these experiments and information available in the literature support the hypothesis that these responses are due to an interference in the autonomic pathways that modulate cardiovascular function.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1984
- Accession Number
- ADA151157
Entities
People
- C. R. Lake
- George N. Catravas
- R. N. Hawkins
- W. A. Alter Iii
Organizations
- Armed Forces Radiobiology Research Institute