Action potential configuration in heart papillary muscles from female rats in different thyroid states

Archives of Physiology and Biochemistry
S Di MeoT De Leo

Abstract

We have studied the effects of thyroidectomy and the in vivo administration of different triiodothyronine (T3) doses in thyroidectomized female rats on electrophysiological properties, measured in vitro, of the anterior and posterior papillary muscle fibers from the right ventricle. In each thyroid state, the action potential duration (APD) measured by stimulating at 1 Hz was shorter for the posterior papillary muscle. APD from both preparations was found significantly lengthened in thyroidectomized animals in comparison to euthyroid controls. APD was shortened owing to treatment of thyroidectomized rats with T3 doses up to 10 micrograms/100 g body weight every second day. Treatment with larger doses of T3 tended to restore the values of APD found for ventricular fibres from both controls and thyroidectomized animals treated with substitutive T3 doses (5 micrograms/100 g body weight every second day). As the stimulation rate was increased from 1 to 5 Hz, APD increased in both preparations of all groups. The changes were of different amounts but the APD difference between the rat groups, which were significant at 1 Hz, remained significant at 5 Hz, while the differences between anterior and posterior preparations were cancelled ...Continue Reading

References

Oct 19, 1977·Pflügers Archiv : European journal of physiology·G Isenberg
Jan 1, 1977·General Pharmacology·C IoannidesD V Parke
Jan 1, 1978·Biochemical Pharmacology·R C RumbaughH D Colby
Jul 9, 1992·The New England Journal of Medicine·K A Woeber
Jun 1, 1990·The American Journal of Medicine·W H Dillmann
Feb 1, 1985·Journal of Molecular and Cellular Cardiology·N A SharpR L Parsons
Apr 1, 1988·The Journal of Clinical Investigation·H H SamuelsZ S Ye
Sep 1, 1970·The American Journal of Physiology·E S BlesaS D Serena
May 1, 1984·The Journal of Physiology·M R Boyett, D Fedida
Mar 1, 1983·Circulation Research·T WatanabeT F McDonald
Feb 1, 1981·Journal of Molecular and Cellular Cardiology·M D PayetE Ruiz-Ceretti
Dec 22, 1993·Molecular and Cellular Biochemistry·E K SeppetN S Dhalla

Citations

Jul 7, 2011·Journal of Bioenergetics and Biomembranes·P VendittiS Di Meo

Related Concepts

Nerve Impulses
Basal Metabolic Rate
Electrophysiology (Science)
Pulse Rate
Hyperthyroidism
Structure of Papillary Muscle
Thyroid Gland
Thyroidectomy
Cytomel
Rats, Wistar

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Lipidomics & Rhinovirus Infection

Lipidomics can be used to examine the lipid species involved with pathogenic conditions, such as viral associated inflammation. Discovered the latest research on Lipidomics & Rhinovirus Infection.

Spatio-Temporal Regulation of DNA Repair

DNA repair is a complex process regulated by several different classes of enzymes, including ligases, endonucleases, and polymerases. This feed focuses on the spatial and temporal regulation that accompanies DNA damage signaling and repair enzymes and processes.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Torsion Dystonia

Torsion dystonia is a movement disorder characterized by loss of control of voluntary movements appearing as sustained muscle contractions and/or abnormal postures. Here is the latest research.

Archaeal RNA Polymerase

Archaeal RNA polymerases are most similar to eukaryotic RNA polymerase II but require the support of only two archaeal general transcription factors, TBP (TATA-box binding protein) and TFB (archaeal homologue of the eukaryotic general transcription factor TFIIB) to initiate basal transcription. Here is the latest research on archaeal RNA polymerases.

Alzheimer's Disease: MS4A

Variants within the membrane-spanning 4-domains subfamily A (MS4A) gene cluster have recently been implicated in Alzheimer's disease in genome-wide association studies. Here is the latest research on Alzheimer's disease and MS4A.

Central Pontine Myelinolysis

Central Pontine Myelinolysis is a neurologic disorder caused most frequently by rapid correction of hyponatremia and is characterized by demyelination that affects the central portion of the base of the pons. Here is the latest research on this disease.

Related Papers

Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
P VendittiT De Leo
Comparative Biochemistry and Physiology. B, Comparative Biochemistry
O A Schjeide
International Journal of Developmental Neuroscience : the Official Journal of the International Society for Developmental Neuroscience
E A RivasS Fiszer de Plazas
© 2021 Meta ULC. All rights reserved