Related Experiment Video
Updated: Aug 7, 2026

Intracoronary Acetylcholine Provocation Testing for Assessment of Coronary Vasomotor Disorders
Published on: August 18, 2016
Effects of acetylcholine on internal intercostal muscle activity in the rabbit
1First Department of Physiology, Fukushima Medical College, Japan.
Abstract:
In pentobarbitone-anesthetized rabbits, intracarotid injections of acetylcholine (ACh, 3-30 micrograms) during inspiration led to an inhibition of internal intercostal muscle activity (IIMA). After the section of the carotid sinus nerve (CSN), ACh-induced inhibitory responses in IIMA were abolished. In addition, changes of the rabbit carotid chemoreceptor activity were studied by ACh (3-30 micrograms) given into the carotid body region during inspiration. Spontaneous chemoreceptor activity was inhibited in a dose-dependent manner by ACh. These results suggest that the inhibitory responses of IIMA to ACh are probably mediated through the carotid chemoreceptor reflexes.
More Related Videos
Related Concept Videos
Muscle Contraction
Muscle Contraction
Cholinergic Receptors: Muscarinic
The subtypes M1, M3, and M5 couple with the Gq subunit and activate the phospholipase C (PLC) activity, mobilizing intracellular Ca2+. Activation...
Direct-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
The direct-acting...
Direct-Acting Cholinergic Agonists: Pharmacological Actions
Smooth Muscle Contraction
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...

