Related Experiment Video
Updated: Aug 12, 2026
08:08
Monitoring the Effect of Osmotic Stress on Secretory Vesicles and Exocytosis
Published on: February 19, 2018
The hydrosmotic effect of vasopressin: a scanning electrom-microscope study
The Journal of Membrane Biology
|August 29, 1975
Summary
Vasopressin, combined with an osmotic gradient, reduces microvilli on toad bladder granular cells. This effect, mediated by cAMP or theophylline, highlights granular cells' role in water absorption.
Area of Science:
- Cell Biology
- Physiology
- Microscopy
Background:
- The toad urinary bladder is a model for studying water transport.
- Vasopressin regulates water permeability in epithelial tissues.
- Scanning electron microscopy (SEM) allows visualization of cell surface morphology.
Purpose of the Study:
- To investigate the effect of vasopressin on the apical surface of toad urinary bladders using SEM.
- To identify specific cell types involved in the hydrosmotic response.
Main Methods:
- Urinary bladders from toads (Bufo marinus) were exposed to vasopressin and osmotic gradients.
- Water fluxes were monitored optically.
- Tissues were prepared for SEM to examine epithelial surface changes.
Main Results:
- Vasopressin and an osmotic gradient caused a significant reduction in blunt microvilli on granular cells.
- Mitochondria-rich cells with longer microvilli remained unaffected.
- Similar results were observed with cAMP and theophylline, indicating a conserved signaling pathway.
Conclusions:
- The hydrosmotic effect of vasopressin in toad bladders is primarily mediated by granular cells.
- SEM provides valuable insights into the cellular mechanisms of hormone-induced water transport.
