Cardiovascular effects of 1,8-cineole, a terpenoid oxide present in many plant essential oils, in normotensive rats
In: Canadian Journal of Physiology and Pharmacology, Jg. 80 (2002-12-01), S. 1125-1131
Online
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Zugriff:
The cardiovascular effects of i.v. treatment with 1,8-cineole, a monoterpenic oxide present in many plant essential oils, were investigated in normotensive rats. This study examined (i) whether the autonomic nervous system is involved in the mediation of 1,8-cineole-induced changes in mean aortic pressure (MAP) and heart rate (HR) and (ii) whether the hypotensive effects of 1,8-cineole could result from its vasodilatory effects directly upon vascular smooth muscle. In both pentobarbital-anesthetized and conscious, freely moving rats, bolus injections of 1,8-cineole (0.310 mg/kg, i.v.) elicited similar and dose-dependent decreases in MAP. Concomitantly, 1,8-cineole significantly decreased HR only at the highest dose (10 mg/kg). Pretreatment of anesthetized rats with bilateral vagotomy significantly reduced the bradycardic responses to 1,8-cineole (10 mg/kg) without affecting hypotension. In conscious rats, i.v. pretreatment with methylatropine (1 mg/kg), atenolol (1.5 mg/kg), or hexamethonium (30 mg/kg) had no significant effects on the 1,8-cineole-induced hypotension, while bradycardic responses to 1,8-cineole (10 mg/kg) were significantly reduced by methylatropine. In rat isolated thoracic aorta preparations, 1,8-cineole (0.0062.6 mM) induced a concentration-dependent reduction of the contraction induced by potassium (60 mM). This is the first physiological evidence that i.v. treatment with 1,8-cineole in either anesthetized or conscious rats elicits hypotension; this effect seems related to an active vascular relaxation rather than withdrawal of sympathetic tone.Key words: 1,8-cineole, essential oil, cardiovascular effects, autonomic nervous system, isolated thoracic aorta.
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Cardiovascular effects of 1,8-cineole, a terpenoid oxide present in many plant essential oils, in normotensive rats
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Autor/in / Beteiligte Person: | José Henrique Leal-Cardoso ; Pedro Jorge Caldas Magalhães ; André Fernandes Figueiredo ; Lahlou, Saad |
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Zeitschrift: | Canadian Journal of Physiology and Pharmacology, Jg. 80 (2002-12-01), S. 1125-1131 |
Veröffentlichung: | Canadian Science Publishing, 2002 |
Medientyp: | unknown |
ISSN: | 1205-7541 (print) ; 0008-4212 (print) |
DOI: | 10.1139/y02-142 |
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