Effects of whole- and partial-body irradiation on circulating anterior pituitary hormones and testosterone and the relationship of these hormones to drug-metabolizing enzymes in the liver. [Gamma radiation, rats]
Doses within the range of 850 to 1500 rad given to the whole body, head, or lower-trunk region of male rats cause a marked depression in the rate of oxidative demethylation of drugs in the liver endoplasmic reticulum, 3 to 4 days after the irradiation. The V/sub max/ of the enzyme system is depressed and the K/sub m/ increased. Irradiation to the whole body, head, or lower trunk also causes a fall in the circulating levels of testosterone and luteinizing hormone (LH) and the concentrations of these hormones are markedly reduced 3 to 4 days after the irradiation. Injections of testosterone or anterior pituitary extract effectively restore the activity of the liver enzyme system after irradiation of the head or lower trunk. It is concluded that whole-body irradiation causes inhibition of drug-metabolizing enzymes in the liver by a complex series of interrelated effects on the testis, anterior pituitary, and possibly the hypothalamus.
- Research Organization:
- Medical College of St. Bartholomew's Hospital, London
- OSTI ID:
- 5334157
- Journal Information:
- Radiat. Res.; (United States), Vol. 72:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ENZYMES
BIOLOGICAL RADIATION EFFECTS
PITUITARY HORMONES
TESTOSTERONE
COMPARATIVE EVALUATIONS
GAMMA RADIATION
LIVER
METABOLISM
PARTIAL BODY IRRADIATION
RATS
WHOLE-BODY IRRADIATION
ANDROGENS
ANDROSTANES
ANIMALS
BIOLOGICAL EFFECTS
BODY
DIGESTIVE SYSTEM
ELECTROMAGNETIC RADIATION
EXTERNAL IRRADIATION
GLANDS
HORMONES
HYDROXY COMPOUNDS
IONIZING RADIATIONS
IRRADIATION
KETONES
MAMMALS
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
RADIATION EFFECTS
RADIATIONS
RODENTS
STEROID HORMONES
STEROIDS
VERTEBRATES
560114* - Radiation Effects on Biochemicals- In Animals- (-1987)
560152 - Radiation Effects on Animals- Animals