Cardiovascular effects of benzquinamide
Anesthesia and Analgesia
|May 1, 1979
Summary
Benzquinamide causes tachycardia and arrhythmias in dogs by affecting vascular smooth muscle and sympathetic activation. Ganglionic blockade alters these cardiovascular responses.
Area of Science:
- Pharmacology
- Cardiovascular Physiology
Background:
- Benzquinamide is a drug with potential cardiovascular effects.
- Understanding its impact on the cardiovascular system is crucial for its clinical application.
Purpose of the Study:
- To evaluate the cardiovascular effects of benzquinamide in anesthetized dogs.
- To investigate the mechanisms underlying these effects, including vascular smooth muscle and sympathetic nervous system involvement.
Main Methods:
- Intravenous administration of benzquinamide (0.5-5 mg/kg) in anesthetized dogs.
- Assessment of cardiovascular parameters including heart rate, blood pressure, and arrhythmias.
- Evaluation of blood norepinephrine levels.
- Studies on isolated mesenteric arterial preparations to assess vascular smooth muscle response.
- Ganglionic blockade with hexamethonium to elucidate the role of autonomic ganglia.
Main Results:
- Benzquinamide induced tachycardia, elevated blood norepinephrine, ventricular arrhythmias, and transient hypotension.
- Ganglionic blockade abolished tachycardia and norepinephrine changes but prolonged hypotension.
- Benzquinamide impaired contractile responses in isolated mesenteric arteries to various stimuli.
- Evidence suggests direct vascular smooth muscle relaxation by benzquinamide.
Conclusions:
- Benzquinamide directly relaxes vascular smooth muscle, leading to reduced peripheral resistance and hypotension.
- Reflex sympathetic activation compensates for the hypotensive effects.
- The drug's cardiovascular profile involves both direct vascular actions and indirect autonomic responses.
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