Related Experiment Videos
Cholinergic agents inhibit sodium transport across the isolated toad bladder
The American Journal of Physiology
|December 1, 1978
Summary
Cholinergic agents like acetylcholine inhibit sodium transport in toad bladders by affecting calcium and cyclic GMP levels. These effects, mediated by atropine, highlight a complex regulatory mechanism.
Area of Science:
- Physiology
- Cell Biology
- Pharmacology
Background:
- Cholinergic agents, such as acetylcholine, play a role in regulating epithelial transport.
- Calcium and cyclic GMP are known intracellular messengers involved in cellular processes.
Purpose of the Study:
- To investigate the effects of cholinergic agents on sodium transport in toad bladders.
- To elucidate the role of calcium and cyclic GMP in mediating these cholinergic effects.
Main Methods:
- Studied the inhibition of sodium transport by acetylcholine and carbamylcholine (carbachol) in toad bladders.
- Measured 45Ca uptake and cyclic GMP levels in isolated toad bladder epithelial cells.
- Utilized atropine, pentobarbital, and lanthanum chloride to block specific pathways.
Main Results:
- Acetylcholine and carbachol inhibited sodium transport, an effect blocked by atropine.
- Carbachol increased 45Ca uptake and cyclic GMP levels in epithelial cells, both blocked by atropine.
- The inhibition of sodium transport was dependent on external calcium and blocked by calcium-entry inhibitors.
Conclusions:
- Cholinergic agents inhibit sodium transport in toad bladders, involving calcium influx and potentially cyclic GMP.
- Further research is needed to determine if calcium, cyclic GMP, or both mediate the observed decrease in sodium transport.