Alterations in rat cardiac myosin isozymes induced by whole-body irradiation are prevented by 3,5,3'-L-triiodothyronine

Journal Article · Mon Jan 01 00:00:00 EST 1990 · Metabolism, Clinical and Experimental; (USA)

DOI:https://doi.org/10.1016/0026-0495(90)90149-7· OSTI ID:7104856

Litten, R Z; Fein, H G; Gainey, G T; Walden, T L; Smallridge, R C ^[1]

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1. Armed Forces Radiobiology Research Institute, Bethesda, MD (USA)

Changes in cardiac myosin isozymes and serum thyroid hormone levels were investigated in rats following 10 Gy whole-body gamma irradiation. The percent beta-myosin heavy chain increased from 21.3 {plus minus} 1.8 to 28.1 {plus minus} 6.8 (NS) at 3-day postirradiation, 37.7 {plus minus} 1.9 (P less than .001) at 6-day postirradiation, and 43.8 {plus minus} 3.3 (P less than .001) at 9-day postirradiation. Along with the change in myosin isozymes was a significant 53% decrease (P less than .001) in the serum thyroxine (T4) level by day 3 postirradiation, remaining depressed through day 9 postirradiation. The serum 3,5,3'-triiodothyronine (T3) level, however, was normal until day 9, when significant depression was also observed. In contrast, the thyroid-stimulating hormone (TSH) level was significantly increased by fourfold at day 3, returning to near normal values by day 9 postirradiation. Daily injections of physiological doses of T3 (0.3 microgram/100 g body weight) prevented the change in the myosin isozymes following whole-body irradiation. Daily pharmacological injections of T3 (3.0 micrograms/100 g body weight) to the irradiated rats produced a further decrease in the percent beta-myosin heavy chain (below control values) indicating tissue hyperthyroidism. Thus, this study suggests that the change in myosin isozymes following whole-body irradiation is caused by an alteration in thyroid hormone activity.

• OSTI ID: 7104856
• Journal Information: Metabolism, Clinical and Experimental; (USA), Vol. 39:1; ISSN 0026-0495
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
MYOSIN
BIOSYNTHESIS
TRIIODOTHYRONINE
RADIOSENSITIVITY EFFECTS
BIOLOGICAL RADIATION EFFECTS
GAMMA RADIATION
HEART
HYPERTHYROIDISM
RATS
THYROXINE
TSH
WHOLE-BODY IRRADIATION
AMINO ACIDS
ANIMALS
BIOLOGICAL EFFECTS
BODY
CARBOXYLIC ACIDS
CARDIOVASCULAR SYSTEM
DISEASES
ELECTROMAGNETIC RADIATION
ENDOCRINE DISEASES
EXTERNAL IRRADIATION
GLOBULINS
HORMONES
IONIZING RADIATIONS
IRRADIATION
MAMMALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
ORGANS
PEPTIDE HORMONES
PITUITARY HORMONES
PROTEINS
RADIATION EFFECTS
RADIATIONS
RODENTS
SYNTHESIS
THYROID HORMONES
VERTEBRATES
560152* - Radiation Effects on Animals- Animals