In-vitro characterization of the pharmacological effects induced by (-)-α-bisabolol in rat smooth muscle preparations.
Can J Physiol Pharmacol
; 90(1): 23-35, 2012 Jan.
Article
in En
| MEDLINE
| ID: mdl-22171824
ABSTRACT
The present study deals with the pharmacological effects of the sesquiterpene alcohol (-)-α-bisabolol on various smooth-muscle preparations from rats. Under resting tonus, (-)-α-bisabolol (30-300 µmol/L) relaxed duodenal strips, whereas it showed biphasic effects in other preparations, contracting endothelium-intact aortic rings and urinary bladder strips, and relaxing these tissues at higher concentrations (600-1000 µmol/L). In preparations precontracted either electromechanically (by 60 mmol/L K(+)) or pharmacomechanically (by phenylephrine or carbachol), (-)-α-bisabolol showed only relaxing properties. The pharmacological potency of (-)-α-bisabolol was variable, being higher in mesenteric vessels, whereas it exerted relaxing activity with a lesser potency on tracheal or colonic tissues. In tissues possessing spontaneous activity, (-)-α-bisabolol completely decreased spontaneous contractions in duodenum, whereas it increased their amplitude in urinary bladder tissue. Administered in vivo, (-)-α-bisabolol attenuated the increased responses of carbachol in tracheal rings of ovalbumin-sensitized rats challenged with ovalbumin, but was without effect in the decreased responsiveness of urinary bladder strips in mice treated with ifosfamide. In summary, (-)-α-bisabolol is biologically active in smooth muscle. In some tissues, (-)-α-bisabolol preferentially relaxed contractions induced electromechanically, especially in tracheal smooth muscle. The findings from tracheal rings reveal that (-)-α-bisabolol may be an inhibitor of voltage-dependent Ca(2+) channels.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Sesquiterpenes
/
Muscle Contraction
/
Muscle Relaxation
/
Muscle, Smooth
Type of study:
Prognostic_studies
Limits:
Animals
Language:
En
Journal:
Can J Physiol Pharmacol
Year:
2012
Document type:
Article
Affiliation country: