Cardiovascular effects of the essential oil of Mentha x villosa in DOCA-salt-hypertensive rats.
The present study investigated the effects of chronic treatment with deoxycorticosterone-acetate (DOCA)-salt on cardiovascular responses to intravenous (i.v.) injection of the essential oil of Mentha x villosa (EOMV) in conscious rats. In both DOCA-salt-hypertensive and uninephrectomized control, conscious rats, i.v. bolus injections of EOMV (1 to 20 mg/kg body wt.) decreased mean aortic pressure (MAP) and heart rate (HR) in a dose-dependent manner. Treatment with DOCA-salt significantly enhanced EOMV-induced decreases in MAP, without affecting bradycardia. Likewise, both maximal percent and absolute decreases in MAP elicited by i.v. injection of the ganglion blocker, hexamethonium (30 mg/kg body wt.), were significantly greater in DOCA-salt-hypertensive than in control rats. In DOCA-salt-hypertensive rats, i.v. pretreatment with hexamethonium (30 mg/kg body wt.) reduced the bradycardia elicited by EOMV (1 to 20 mg/kg body wt.) without affecting the enhancement of EOMV-induced hypotension. These results show that i.v. treatment with EOMV decreases blood pressure in conscious DOCA-salt-hypertensive rats dose-dependently, and that this action is enhanced when compared with uninephrectomized controls. This enhancement could be related mainly to an increase in EOMV-induced vascular smooth muscle relaxation, rather than to enhanced sympathetic nervous system activity in this hypertensive model.
Lahlou
S
S
Departamento de Fisiologia e Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Pernambuco, Recife-PE, Brasil. lahlou@npd.ufpe.br
Carneiro-Leão
R Ferreira Lima
RF
Leal-Cardoso
J H
JH
D000818:Animals; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D001013:Aorta, Thoracic / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects*; D003900:Desoxycorticosterone; D004305:Dose-Response Relationship, Drug; D006339:Heart Rate / Q000187:drug effects*; D006973:Hypertension / Q000139:chemically induced / Q000188:drug therapy; D007275:Injections, Intravenous; D008297:Male; D027541:Mentha; D008517:Phytotherapy; D010938:Plant Oils / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar
D000959:Antihypertensive Agents; D010938:Plant Oils; D003900:Desoxycorticosterone