Chronic ethanol attenuates centrally-mediated hypotension elicited via alpha(2)-adrenergic, but not I(1)-imidazoline, receptor activation in female rats.
Life Sci
; 84(3-4): 111-8, 2009 Jan 16.
Article
em En
| MEDLINE
| ID: mdl-19041658
ABSTRACT
AIMS:
This study dealt with the effect of chronic ethanol administration on hemodynamic responses elicited by alpha(2)-adrenergic (alpha-methyldopa) or I(1)-imidazoline (rilmenidine) receptor activation in telemetered female rats. MAINMETHODS:
The effects of alpha-methyldopa or rilmenidine on blood pressure (BP), heart rate (HR) and their variability were investigated in rats that received liquid diet without or with ethanol (5% w/v) for 12 weeks. To evaluate the effect of each drug on cardiovascular autonomic control (BP and HR variability) in the absence or presence of ethanol, three time-domain indices of hemodynamic variability were measured (i) standard deviation of mean arterial pressure (SDMAP), (ii) standard deviation of beat-to-beat intervals, and (iii) root mean square of successive differences in R-R intervals. KEYFINDINGS:
In liquid diet-fed control rats, i.p. rilmenidine (600 microg/kg) or alpha-methyldopa (100 mg/kg) reduced BP along with decreases and increases, respectively, in HR. Both drugs had no effect on HR variability but reduced BP variability (SDMAP), suggesting a reduced vasomotor sympathetic tone. Ethanol feeding attenuated reductions in BP and SDMAP evoked by alpha-methyldopa but not by rilmenidine.SIGNIFICANCE:
We conclude that chronic ethanol preferentially compromises alpha(2)- but not I(1)-receptor-mediated hypotension in female rats probably via modulation of vasomotor sympathetic activity. These findings highlight the adequacy of rilmenidine use to lower BP in hypertensive alcoholic females.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Pressão Sanguínea
/
Receptores Adrenérgicos alfa 2
/
Etanol
/
Receptores de Imidazolinas
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Life Sci
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Estados Unidos