Related Experiment Video
Updated: Aug 18, 2026

Bladder Smooth Muscle Strip Contractility as a Method to Evaluate Lower Urinary Tract Pharmacology
Published on: August 18, 2014
Neuronal norepinephrine as mediator for ouabain-induced smooth muscle contraction
Abstract:
With some latency, ouabain (10(-6)--10(-5) M) induced a long-lasting contractile response of the isolated vas deferens of the guinea-pig. The ouabain-induced contraction was potentiated by pretreatment with tropolone, whereas it was prevented by pretreatment with cocaine, bretylium, reserpine or phentolamine. The response was unaffected byatropine, methysergide and tetrodotoxin. Ouabain, perfused into the isolated tissue, enhanced dose-dependently the release of norepinephrine into the medium. However, this enhancement of norepinephrine release was prevented by reserpine or by removal of Ca from the medium. These findings support the hypothesis that the ouabain-induced contraction of vas deferens might be due to norepinephrine released from the adrenergic nerve ending granules through a Ca2+-dependent process.
More Related Videos
09:05Measurement of Smooth Muscle Function in the Isolated Tissue Bath-applications to Pharmacology Research
Published on: January 19, 2015
08:41Assessment of Vascular Tone Responsiveness using Isolated Mesenteric Arteries with a Focus on Modulation by Perivascular Adipose Tissues
Published on: June 3, 2019
Related Concept Videos
Nitric Oxide Signaling Pathway
Adrenergic Neurons: Neurotransmission
Synthesis: Catecholamine synthesis requires tyrosine, which is taken...
Adrenergic Agonists: Direct-Acting Agents
These agents can be classified...
Adrenergic Agonists: Indirect-Acting Agents
One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral bioavailability, and...
Drugs Affecting Neurotransmitter Release or Uptake
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...