Thromboxane-mediated injury following radiation. Annual report, 1 September 1985-17 June 1986, Final report 15 January 1984-17 June 1986
Previous studies demonstrated an increased in-vivo and in-vitro release of immunoreactive thromboxane B2 (TXB2) four hours after 20.0-Gy whole-body irradiation. This radiation-induced increase in TXB2 release was of extrarenal origin. This report confirms that whole-body ionizing radiation exposure results in an increased pulmonary TXB2 release. Since radiation exposure is associated with an increased release of TXB2, the present studies sought to determine if tissue responsiveness was altered to this cyclooxygenase product. Rats were anesthetized (30 mg/kg sodium pentobarbital, i.p.) and exposed to 20.0 Gy whole-body gamma irradiation. The effect of the radioprotectant, WR2721, on the radiation-induced depression in vascular reactivity was assessed next. The release of TXB2 from the pulmonary bed of irradiated animals was determined. These results indicate the importance of a plasma-like perfusate in studying cyclooxygenase product release from isolated organs. The data also show that radiation exposure will depress vascular reactivity to the TXA2 mimic, U46619. This radiation-induced alteration in vascular reactivity was preventable by treatment of the animals with the radioprotectant, WR2721, prior to irradiation. These results suggest that the altered release of TXB2 seen following lethal doses of gamma radiation may have both physiological ramifications and pharmacological applications.
- Research Organization:
- Georgetown Univ., Washington, DC (USA)
- OSTI ID:
- 5130831
- Report Number(s):
- AD-A-186556/7/XAB
- Country of Publication:
- United States
- Language:
- English
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CARDIOVASCULAR SYSTEM
BIOLOGICAL RADIATION EFFECTS
BIOCHEMISTRY
PHARMACOLOGY
PROGRESS REPORT
RADIOPROTECTIVE SUBSTANCES
RATS
WHOLE-BODY IRRADIATION
ANIMALS
BIOLOGICAL EFFECTS
CHEMISTRY
DOCUMENT TYPES
DRUGS
EXTERNAL IRRADIATION
IRRADIATION
MAMMALS
RADIATION EFFECTS
RODENTS
VERTEBRATES
560152* - Radiation Effects on Animals- Animals