Morphine tolerance offers protection from radiogenic performance deficits
When rats are exposed to a sufficiently large dose of ionizing radiation they exhibit lethargy, hypokinesia, and deficits in performance. These and other behavioral changes parallel those often observed in this species after a large dose of morphine. Since the release of endogenous opiates has been implicated in some stress reactions, we sought to determine if they might play a part in radiogenic behavioral deficits. Rats were trained to criterion on a signaled avoidance task. Some subjects were then implanted with a pellet containing 75 mg of morphine. Other animals received placebo implants. Over a number of days, morphine tolerance was evaluated by measurement of body temperature changes. Prior to 2500 rad /sup 60/Co exposure or sham irradiation, morphine (or placebo) pellets were removed. Twenty-four hours later rats were retested to assess their performance on the avoidance task. Morphine-tolerant subjects performed significantly better than the irradiated placebo-implanted group and no differently than morphine-tolerant/sham-irradiated animals. Morphine tolerance seems to provide a degree of behavioral radiation resistance. These data are consistent with the hypothesis that endogenous opiate hyperexcretion may play some part in the behavioral deficits often observed after irradiation.
- Research Organization:
- Department of Behavioral Sciences and Leadership, United States Air Force Academy, Colorado
- OSTI ID:
- 6253373
- Journal Information:
- Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Journal Issue: 2 Vol. 93:2; ISSN RAREA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
560152* -- Radiation Effects on Animals-- Animals
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALKALOIDS
ANALGESICS
ANIMALS
BEHAVIOR
BIOLOGICAL EFFECTS
BIOLOGICAL PATHWAYS
BIOLOGICAL RADIATION EFFECTS
CENTRAL NERVOUS SYSTEM DEPRESSANTS
DRUGS
MAMMALS
MORPHINE
NARCOTICS
OPIUM
ORGANIC COMPOUNDS
RADIATION EFFECTS
RADIOPROTECTIVE SUBSTANCES
RADIOSENSITIVITY
RADIOSENSITIVITY EFFECTS
RATS
RODENTS
TOLERANCE
VERTEBRATES