Behavioral and physiological changes produced by a supralethal dose of ionizing radiation: evidence for hormone-influenced sex differences in the rat
A sufficiently large and rapid dose of ionizing radiation produces an immediate but transient behavioral incapacitation. Acute hypotension often accompanies the disorder. Although the etiology of this syndrome is unclear, it has been suggested that an increase in histamine excretion contributes to it. Since histamine is known to interact with the endocrine system and since estrogens have been shown to prolong the life of animals exposed to potentially lethal doses of radiation, it was also hypothesized that females might be relatively less affected by an acute, large dose of ionizing radiation. Male and female rats were trained on an avoidance task, irradiated, and then retested. Females showed a less severe decrement after radiation exposure than males. Likewise, females did not suffer the severe hypotension normally associated with male radiogenic early transient incapacitation (ETI); rather, an acute hypertension was produced in females. A second series of experiments revealed that differences in male and female radiation response were eliminated by gonadectomy. Systemic estradiol injection produced strikingly feminine (i.e., superior) postirradiation avoidance responses as well as hypertension in neutered rats. Testosterone injections had no effect on either measure. Central nervous system alterations have been correlated with the ETI. Therefore, final experiments sought a possible central locus of the action of estradiol. It was found that exposure of the nucleus peopticus medialis to estrogens produces postirradiation benefits in avoidance performance and blood pressure similar to those seen after systemic estradiol treatments. Nucleus amygdaloideus medialis implants produced no such benefits.
- Research Organization:
- Armed Forces Radiobiology Research Inst., Bethesda, MD
- OSTI ID:
- 5463223
- Journal Information:
- Radiat. Res.; (United States), Vol. 81:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ELECTRONS
BIOLOGICAL RADIATION EFFECTS
HYPERTENSION
RADIOINDUCTION
HYPOTENSION
IONIZING RADIATIONS
RADIOSENSITIVITY
SEX DEPENDENCE
BEHAVIOR
CASTRATION
COMPARATIVE EVALUATIONS
ESTRADIOL
EXPERIMENTAL DATA
FEMALES
ISOLATED VALUES
MALES
RATS
ANIMALS
BIOLOGICAL EFFECTS
CARDIOVASCULAR DISEASES
DATA
DATA FORMS
DISEASES
ELEMENTARY PARTICLES
ESTRANES
ESTROGENS
FERMIONS
HORMONES
HYDROXY COMPOUNDS
INFORMATION
LEPTONS
MAMMALS
MEDICINE
NUMERICAL DATA
ORGANIC COMPOUNDS
RADIATION EFFECTS
RADIATIONS
RODENTS
STEROID HORMONES
STEROIDS
SURGERY
SYMPTOMS
VASCULAR DISEASES
VERTEBRATES
560152* - Radiation Effects on Animals- Animals
550100 - Behavioral Biology