title: Physiological significance of P2X receptor-mediated vasoconstriction in five different types of arteries in rats.
abstract: P2X(1) receptors, the major subtype of P2X receptors in the vascular smooth muscle, are essential for α,β-methylene adenosine 5'-triphosphate (α,β-MeATP)-induced vasoconstriction. However, relative physiological significance of P2X(1) receptor-regulated vasoconstriction in the different types of arteries in the rat is not clear as compared with α(1)-adrenoceptor-regulated vasoconstriction. In the present study, we found that vasoconstrictive responses to noncumulative administration of α,β-MeATP in the rat isolated mesenteric arteries were significantly smaller than those to single concentration administration of α,β-MeATP. Therefore, we firstly reported the characteristic of α,β-MeATP-regulated vasoconstrictions in rat tail, internal carotid, pulmonary, mesenteric arteries, and aorta using single concentration administration of α,β-MeATP. The rank order of maximal vasoconstrictions for α,β-MeATP (E (max·α,β-MeATP)) was the same as that of maximal vasoconstrictions for noradrenaline (E (max·NA)) in the internal carotid, pulmonary, mesenteric arteries, and aorta. Moreover, the value of (E (max·α,β-MeATP)/E (max·KCl))/(E (max·NA)/E (max·KCl)) was 0.4 in each of the four arteries, but it was 0.8 in the tail artery. In conclusion, P2X(1) receptor-mediated vasoconstrictions are equally important in rat internal carotid, pulmonary, mesenteric arteries, and aorta, but much greater in the tail artery, suggesting its special role in physiological function.
authors.affiliation: Department of Pharmacology, Institute of Chinese Integrative Medicine, Hebei Medical University, 361 East Zhong-shan Road, Shijiazhuang, 050017, Hebei, People's Republic of China.
authors.forename: Lu
authors.initials: L
authors.lastname: Li
authors.forename: Zhen-Hua
authors.initials: ZH
authors.lastname: Jia
authors.forename: Chao
authors.initials: C
authors.lastname: Chen
authors.forename: Cong
authors.initials: C
authors.lastname: Wei
authors.forename: Jian-Ke
authors.initials: JK
authors.lastname: Han
authors.forename: Yi-Ling
authors.initials: YL
authors.lastname: Wu
authors.forename: Lei-Ming
authors.initials: LM
authors.lastname: Ren