Tachyphylaxis and sensitization to nicotine-induced tachycardiac and pressor effects after nicotine infusions
Arch. med. res
;
28(2): 189-94, jul. 1997. tab, ilus
Article
in English
| LILACS
| ID: lil-225213
RESUMO
This work examined the effects of nicotine on mean arterial pressure and heart rate in non-anesthetized as a single bolus, as infusions lasting 7.5, 15 or 30 min, and as a post-infusion bolus. A nicotine bolus increased pressure and rate. These effects were less marked as the rate of infusion decreased. The infusions affected differentially the effects of a subsequent bolus. Thus, while tachycardia was decreased, the blood pressure rise was increased. An initial transiet bradycardia was observed after bolus administration, but not during infusions; this effect was unchaged after post-infusion boluses. Pharmacological analysis indicated that tachycardia and bradycardia were predominantly due to ganglionic stimulation, while adrenal and sumpathetic nerve catecholamine release played a major role in the pressor response., These results indicate that slow nicotine infusions do not induce tachyphylaxis for all of the cardiovascular effects of a subsequent bolus, and that development of acute tolerance appears to depend on the mechanism of action of the response
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Index:
LILACS (Americas)
Main subject:
Blood Pressure
/
Bradycardia
/
Drug Administration Schedule
/
Rats, Wistar
/
Heart Rate
/
Hypertension
/
Injections, Intravenous
/
Nicotine
Limits:
Animals
Language:
English
Journal:
Arch. med. res
Journal subject:
Medicine
Year:
1997
Type:
Article
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