[Potentiating effect of ethanol on alpha 1 adrenergic receptor mediated contraction of thoracic aorta from guinea pig].
Using aortic strips isolated from guinea pigs, effects of ethanol on vascular smooth muscle tonus were studied. 50mM of ethanol significantly potentiated the contractions induced by norepinephrine and phenylephrine, but did not influence those induced by KCl and clonidine. Furthermore, ethanol significantly augmented the contraction induced by phenylephrine in the presence of verapamil, and did not have any effects on the contractions induced by A23187, Ba2+, PDBu and BAY K 8644. These results indicate that ethanol potentiates the alpha 1 adrenergic receptor-mediated contraction, depending on the extracellular calcium influx via the receptor-operated calcium channel.
Masui
H
H
2nd Department of Internal Medicine, Hyogo College of Medicine, Japan.
Wakabayashi
I
I
Hatake
K
K
Yoshimoto
S
S
Nakamura
Y
Y
Seto
Y
Y
Iwata
N
N
Hishida
S
S
Kakishita
E
E
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism; D004357:Drug Synergism; D000431:Ethanol / Q000494:pharmacology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D018340:Receptors, Adrenergic, alpha-1 / Q000187:drug effects*
D000316:Adrenergic alpha-Agonists; D015220:Calcium Channels; D018340:Receptors, Adrenergic, alpha-1; D010656:Phenylephrine; D000431:Ethanol; D002118:Calcium; D009638:Norepinephrine