Related Experiment Video
Updated: Aug 12, 2025

Rodent Working Heart Model for the Study of Myocardial Performance and Oxygen Consumption
Published on: August 16, 2016
Mechanisms of Modulation of Adrenergic Regulation of Spontaneous Activity Rate and Atrial Myocardial Contractility in
N G Iskakov1, T A Anikina2, F G Sitdikov2
1Department of Human Health Protection, Kazan (Volga region) State University, Kazan, Republic of Tatarstan, Russia. nikitaiskakov1992@mail.ru.
Abstract:
We studied combined effect of the β1,2-adrenoreceptor agonist isoproterenol and the Y1,5 receptor agonist [Leu31, Pro34]neuropeptide Y on the frequency of spontaneous activity and myocardial contractility in 21- and 100-day-old rats. Isoproterenol increased the frequency of spontaneous activity and reduced the main parameters of isometric contraction of the atrial myocardium. When [Leu31, Pro34]neuropeptide Y was added, the frequency of spontaneous activity and the negative inotropic and the positive chronotropic effects of isoproterenol were reduced in 100-day-old rats. In 21-day-olds rats, a tendency to a decrease in the effect of isoproterenol was observed.
Related Concept Videos
Regulation of Heart Rates
The SNS increases heart rate through the release of norepinephrine and epinephrine, which act on beta-1 adrenergic receptors in the heart. This action increases the rate of depolarization in the sinoatrial (SA) node, the heart's...
Adrenergic Receptors: β Subtype
Isoprenaline > Adrenaline > Noradrenaline
Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes.
β1-adrenoceptors: β1-adrenoceptors...
Factors Influencing Heart Rate
Let us explore the significant factors affecting heart rate, including age, body temperature, posture, acute pain, chemical influences,...
Sympathetic Signaling
Sympathetic preganglionic fibers release the neurotransmitter acetylcholine (ACh) onto the ganglionic neurons in the...
Adrenergic Receptors (Adrenoceptors): Classification
α-Adrenoceptors
α-Adrenoceptors are classified into two main subtypes: α1 and α2. The α1 adrenoceptors,...
Conduction System of the Heart
The pacemaker cells are located in two primary nodes: the sinoatrial (SA) node and the atrioventricular (AV) node. The SA node pacemaker cells can autonomously depolarize, triggering an action potential that leads to the...

