Effects of thyroid state on respiration of perfused rat and guinea pig hearts

Journal Article · Tue Sep 01 00:00:00 EDT 1987 · American Journal of Physiology; (USA)

OSTI ID:5017117

Read, L C; Wallace, P G; Berry, M N ^[1]

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1. Flinders Univ. School of Medicine, Bedford Park (Australia)

The effects of thyroid state on the respiration of the isolated heart were investigated using retrograde perfused rat and guinea pig hearts. In both species, hypothyroidism caused a marked depression in circulating thyroid hormone concentrations and in the respiration of the isolated, retrograde perfused heart. Hypothyroidism was caused by injecting animals with Na{sup 131}I. The effects on myocardial respiration could be attributed to changes in the contraction frequency and in the oxygen consumption per beat, with little contribution from basal respiration. Treatment of animals with thyroxine elevated plasma thyroid hormones to a similar extent in rats and guinea pigs. In the latter, thyroxine treatment was associated with substantial increases in the contraction frequency and the oxygen consumption per beat of the isolated heart. In contrast, only small changes were apparent in the retrograde perfused rat heart, observations that were confirmed in rat hearts perfused at near physiological work loads. It was concluded that rat hearts isolated from normal animals function at near maximal thyroid state, in contrast to the guinea pig heart, which requires higher circulating concentrations of thyroid hormones to attain maximal responses.

• OSTI ID: 5017117
• Journal Information: American Journal of Physiology; (USA), Vol. 253:3; ISSN 0002-9513
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
59 BASIC BIOLOGICAL SCIENCES
HEART
RESPIRATION
HYPOTHYROIDISM
RADIOINDUCTION
THYROID
PHYSIOLOGY
THYROID HORMONES
RADIOIMMUNOASSAY
GUINEA PIGS
IODINE 131
MYOCARDIUM
PERFUSED ORGANS
RATS
SODIUM IODIDES
THYROXINE
TRIIODOTHYRONINE
ALKALI METAL COMPOUNDS
AMINO ACIDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOASSAY
BODY
CARBOXYLIC ACIDS
CARDIOVASCULAR SYSTEM
DAYS LIVING RADIOISOTOPES
DIAGNOSTIC TECHNIQUES
DISEASES
ENDOCRINE DISEASES
ENDOCRINE GLANDS
GLANDS
HALIDES
HALOGEN COMPOUNDS
HORMONES
IMMUNOASSAY
IMMUNOLOGY
INORGANIC PHOSPHORS
INTERMEDIATE MASS NUCLEI
IODIDES
IODINE COMPOUNDS
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
MUSCLES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
ORGANS
PEPTIDE HORMONES
PHOSPHORS
RADIOASSAY
RADIOIMMUNODETECTION
RADIOIMMUNOLOGY
RADIOISOTOPES
RODENTS
SODIUM COMPOUNDS
TRACER TECHNIQUES
VERTEBRATES
560152* - Radiation Effects on Animals- Animals
550201 - Biochemistry- Tracer Techniques