Effects of thyroid hormone on Na sup + -K sup + transport in resting and stimulated rat skeletal muscle

Journal Article · Tue Nov 01 00:00:00 EST 1988 · American Journal of Physiology; (USA)

OSTI ID:6037101

Everts, M E; Clausen, T ^[1]

---

1. Aarhus Univ. (Denmark)

The effects of hypothyroidism and 3,5,3{prime}-triiodothyronine (T{sub 3}) treatment on passive Na{sup +}-K{sup +} fluxes and Na{sup +}-K{sup +} pump concentration were investigated in isolated rat muscle. Within 12 h after a single dose of T{sub 3} (20 {mu}g/100 g body wt), K{sup +} efflux had increased by 21% in soleus and by 20% in extensor digitorum longus muscle. In the presence of ouabain, even larger effects were observed. These changes were associated with a 12% rise in amiloride-suppressible Na{sup +} influx but no significant increase in ({sup 3}H)ouabain binding site concentration. After 3 days of T{sub 3} treatment, the stimulating effect on K{sup +} efflux and Na{sup +} influx in soleus reached a plateau {approximately}80 and 40% above control levels, respectively, whereas the maximum increase in ({sup 3}H)ouabain binding site concentration (103%) was only fully developed after 8 days. Hypothyroidism decreased {sup 86}Rb efflux by 30%. The efflux of K{sup +} and the influx of Na{sup +} per contraction (both {approximately}7 nmol/g wet wt) as well as the net loss of K{sup +} induced by electrical stimulation were unaffected by T{sub 3} treatment. The rise in resting K{sup +} efflux after 12-24 h of T{sub 3} treatment could be partly blocked by dantrolene or trifluoroperazine, indicating that an increase in the cytoplasmic Ca{sup 2+} concentration may contribute to the early rise in K{sup +} efflux. It is concluded that the early rise in the resting passive leaks of Na{sup +} and K{sup +} induced by T{sub 3} is a major driving force for Na{sup +}-K{sup +} pump synthesis.

• OSTI ID: 6037101
• Journal Information: American Journal of Physiology; (USA), Vol. 255:5; ISSN 0002-9513
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
HYPOTHYROIDISM
BIOLOGICAL EFFECTS
MUSCLES
PHYSIOLOGY
POTASSIUM 42
MEMBRANE TRANSPORT
RUBIDIUM 86
SODIUM 22
TRIIODOTHYRONINE
OUABAIN
POTASSIUM COMPOUNDS
RATS
SODIUM COMPOUNDS
TRITIUM COMPOUNDS
ALKALI METAL COMPOUNDS
ALKALI METAL ISOTOPES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
CARBOHYDRATES
CARDIAC GLYCOSIDES
CARDIOTONICS
CARDIOVASCULAR AGENTS
DAYS LIVING RADIOISOTOPES
DISEASES
DRUGS
ENDOCRINE DISEASES
GLYCOSIDES
HORMONES
HOURS LIVING RADIOISOTOPES
HYDROGEN COMPOUNDS
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LIGHT NUCLEI
MAMMALS
MINUTES LIVING RADIOISOTOPES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PEPTIDE HORMONES
POTASSIUM ISOTOPES
RADIOISOTOPES
RODENTS
RUBIDIUM ISOTOPES
SODIUM ISOTOPES
STROPHANTHINS
THYROID HORMONES
VERTEBRATES
YEARS LIVING RADIOISOTOPES
551001* - Physiological Systems- Tracer Techniques