Effects of irradiation and semistarvation on rat thyrotropin beta subunit messenger ribonucleic acid, pituitary thyrotropin content, and thyroid hormone levels

Journal Article · Mon Jan 01 00:00:00 EST 1990 · Life Sciences; (USA)

DOI:https://doi.org/10.1016/0024-3205(90)90519-W· OSTI ID:6226388

Litten, R Z ^[1]; Carr, F E ^[2]; Fein, H G; Smallridge, R C ^[3]

---

1. Armed Forces Radiology Research Institute, Bethesda, MD (USA)
2. Walter Reed Army Medical Center, Washington, DC (USA)
3. Walter Reed Army Institute of Research, Washington, DC (USA)

The effect of radiation-induced anorexia on serum thyrotropin (TSH), pituitary TSH-{beta} mRNA, pituitary TSH content, serum thyroxine (T{sub 4}), and serum 3,5,3{prime}-triiodothyronine (T{sub 3}) was investigated using feed-matched controls. Rats received 10 Gy gamma whole-body irradiation and were examined 1-3 days postirradiation. Feed-matched and untreated controls were also studied. The average food intake of the irradiated and feed-matched groups was approximately 18% of the untreated controls. Over the three day period both the irradiated and feed-matched groups lost a significant amount of body weight. The serum T{sub 4} levels of both the irradiated and feed-matched groups were not significantly different from each other, but were significantly depressed when compared to the untreated control group. The serum TSH and T{sub 3} were, however, significantly greater in the irradiated than the feed-matched groups at day 3 posttreatment. To determine if the difference in the serum TSH level between the two groups was due to a pretranslational alteration in TSH production, we measured the TSH-{beta} mRNA using an RNA blot hybridization assay. We found that the TSH-{beta} mRNA level was the same in the irradiated and feed-matched groups, suggesting that the mechanism responsible for the radiation-induced increase in the serum TSH level is posttranscriptional. Pituitary TSH content in the irradiated rats was significantly less than in pair-fed controls, suggesting that irradiation may permit enhanced secretion of stored hormone.

• OSTI ID: 6226388
• Journal Information: Life Sciences; (USA), Vol. 47:16; ISSN 0024-3205
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
NERVOUS SYSTEM DISEASES
RADIOINDUCTION
THYRONINE
BIOSYNTHESIS
TRIIODOTHYRONINE
TSH
BIOLOGICAL RADIATION EFFECTS
FASTING
GAMMA RADIATION
MESSENGER-RNA
PITUITARY GLAND
RATS
SECRETION
WHOLE-BODY IRRADIATION
AMINO ACIDS
ANIMALS
BIOLOGICAL EFFECTS
BODY
CARBOXYLIC ACIDS
DISEASES
ELECTROMAGNETIC RADIATION
ENDOCRINE GLANDS
EXTERNAL IRRADIATION
GLANDS
HORMONES
HYDROXY ACIDS
IONIZING RADIATIONS
IRRADIATION
MAMMALS
NUCLEIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
PITUITARY HORMONES
RADIATION EFFECTS
RADIATIONS
RNA
RODENTS
SYNTHESIS
THYROID HORMONES
VERTEBRATES
560152* - Radiation Effects on Animals- Animals