The nasal vasculature plays a critical role in regulating nasal airflow and local tissue homeostasis.
Understanding the effects of vasoactive substances on nasal hemodynamics is essential for managing nasal conditions.
Purpose of the Study:
To investigate the dose-dependent effects of acetylcholine on nasal airway resistance and venous outflow in dogs.
To elucidate the mechanisms underlying acetylcholine-induced changes in nasal vascular resistance.
Main Methods:
Measurements of nasal airway resistance, vascular resistance, and anterior/posterior venous outflow in anesthetized dogs.
Intraarterial administration of acetylcholine at low (< 5 µg/kg/min) and high (> 5 µg/kg/min) doses.
Comparison between dogs with spontaneous nasal blood flow and constant-flow vascular perfusion.
Main Results:
Low-dose acetylcholine increased nasal airway resistance and decreased nasal vascular resistance, with differential effects on anterior and posterior venous outflow.
High-dose acetylcholine decreased both nasal airway resistance and vascular resistance, increasing both anterior and posterior venous outflow.
Responses varied between spontaneous and constant-flow perfusion models, suggesting complex vascular bed interactions.
Conclusions:
Acetylcholine exerts dose-dependent, differential effects on nasal airway resistance and venous outflow.
These findings highlight the complex regulation of the nasal vascular bed by acetylcholine, impacting nasal airflow.
Further research is warranted to explore the clinical implications of these findings in nasal physiology and disease.