A quantitative study of the effects of cholinergic drugs on carotid chemoreceptors in the cat
Related Experiment Video
Updated: Oct 9, 2026

Intracoronary Acetylcholine Provocation Testing for Assessment of Coronary Vasomotor Disorders
Published on: August 18, 2016
Abstract:
1. Conflicting qualitative evidence exists concerning the effects on chemoreceptor activity of some drugs which influence the cholinergic system. Quantitative evidence has been obtained in the present study which should resolve the conflict. 2. Experiments were performed in pentobarbitone-anaesthetized cats in which the activity of chemoreceptor units in the sinus nerve was used to assess chemoreceptor responses. The effects of drugs on responses to I.A. ACH and NaCN were determined from dose-response data obtained from several animals and expressed as mean dose ratios 3. The chemoreceptor response to ACh was slightly inhibited by atropine, alpha- and beta-bungarotoxin and HC-3, almost completely suppressed by mecamylamine, and markedly potentiated by physostigmine. 4. Concomitant responses to NaCN were unaffected by atropine, beta-bungarotoxin, mecamylamine or physostigmine. There was a slight inhibition following alpha-bungarotoxin and a potentiation after HC-3. 5. The results do not support the theory that ACh is an excitatory sensory transmitter in the carotid body.
Related Concept Videos
Direct-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
The direct-acting...
Direct-Acting Cholinergic Agonists: Pharmacokinetics
Direct-Acting Cholinergic Agonists: Pharmacological Actions
Direct-Acting Cholinergic Agonists: Therapeutic Uses
Indirect-Acting Cholinergic Agonists: Pharmacological Actions
At the neuromuscular junction, these agents work by inhibiting the breakdown of acetylcholine, allowing it to remain bound to the receptor and bind to nearby receptors. This process leads to repetitive firing of the endplate, causing muscle...
Cholinergic Antagonists: Pharmacological Actions
Gastrointestinal Effects: Antimuscarinics reduce gut contractions, increase gastric emptying, and slow intestinal transit. They partly inhibit gastric acid secretion...

