.ALPHA.-Adrenoceptors in nasal blood vessels.

スポンサーリンク

概要

• 論文の詳細を見る

• The presence, location and function of the α-adrenoceptors in the blood vessels of the nasal mucosa were evaluated by observing the in vitro vasoactivity to agonists and/or antagonists of the receptors involved. Human nasal mucosa was obtained during turbinectomy from patients with severe nasal allergy or hypertrophic rhinitis, and canine septal mucosa was taken after sacrificing dogs with pentobarbital. Bioassay using an in vitro tension detecting device and radioisotope study quantifying tritium-noradrenaline released from nerve terminals showed existence of prejunctional α-2 adrenoceptors, which posess autoinhibitory effect on noradrenaline release from sympathetic nerve endings. This effect was calcium dependent.In contrast to the ease with which confirmatory evidence for the existence of two subgroups of a-adrenoceptors was obtained in vivo, it has been relatively difficult to demonstrate postjunctional α-2 receptors in vitro so far. This may reflect the fact that α-2 receptors are present in larger numbers in the very small resistance vessels which are not available for in vitro studies with usual vessel specimens. However, they are easily available in the nasal mucosa. The response of the postjunctional α-adrenoceptors of either human or canine mucosa to α-2 agonists (clonidine, B-HT 920) was less in magnitude and slower in speed than that to the α-1 agonist methoxamine. It was obvious especially in the former specimen. Stimulation of both α-1 and α-2 receptors by noradrenaline also mediated vasoconstriction, which was independent of extracellular calcium influx. Phenoxybenzamine, an irreversible antagonist with α-1 selectivity, depressed but did not abolish noradrenaline-induced contractions. The remaining response was not affected by another α-1 specific antagonist prazosin, but was markedly attenuated by the α-2 antagonist yohimbine. These results suggest that human and canine nasal vessels contain both α-1 and α-2 adrenoceptors.

• 耳鼻咽喉科臨床学会の論文

著者

• 周 明仁

  東京大学医学部耳鼻咽喉科学教室

• 市村 恵一

  都立府中病院耳鼻咽喉科

• 関 敦郎

  浜松医科大学耳鼻咽喉科学教室

関連論文

• Therapeutic effect of Neuzym in chronic sinusitis evaluated by densitometry with the copper-step-wedge system.
• 大動脈弁置換手術後の扁桃摘出手術症例について
• Olfactory disturbance caused by perchloroethylene.
• Calcium entry blocker flunarizine for treatment of sudden deafness.
• IgG Deposition in the Lateral Wall of the Endolymphatic Sac in Patients with Menier's Disease
• Cholinergic receptors in the nasal blood vessels of the dog.
• Olfactory disturbance caused by Tegafur; Two cases.
• Immunohistochemical analysis of the lateral wall of the endolymphatic sac of the patients with Meniere's disease:4th report using PAP method
• A clinical study of olfactory disturbance.
• .ALPHA.-Adrenoceptors in nasal blood vessels.

スポンサーリンク