Effects of adenosine tetraphosphate (ATPP) on vascular tone in the isolated rat aorta.
10.3349/ymj.1995.36.6.487
- Author:
Joong Woo LEE
1
;
In Deok KONG
;
Kyu Sang PARK
;
Seong Woo JEONG
Author Information
1. Department of Physiology, Yonsei University Wonju College of Medicine and Institute of Occupational Medicine, Kangwon-Do, Republic of Korea.
- Publication Type:Original Article ; In Vitro ; Research Support, Non-U.S. Gov't
- Keywords:
Adenosine tetraphosphate;
ATP;
P2-purinoceptor;
nucleotide receptor;
endothelium;
vascular smooth muscle;
alpha beta-methylene ATP;
reactive blue 2
- MeSH:
Animal;
Aorta/*drug effects/physiology;
Dinucleoside Phosphates/*pharmacology;
Female;
In Vitro;
Male;
Rats;
Rats, Sprague-Dawley;
Receptors, Purinergic P2/metabolism;
Support, Non-U.S. Gov't;
Vasoconstriction/*drug effects;
Vasodilation/drug effects
- From:Yonsei Medical Journal
1995;36(6):487-496
- CountryRepublic of Korea
- Language:English
-
Abstract:
Effects of a platelet-released, naturally occurring nucleotide, adenosine 5'-tetraphosphate (ATPP) on vascular tone were analyzed in the isolated rat aorta. Under resting tension ATPP (1 approximately 100 microM) elicited concentration-dependent contractions in endothelium-intact aortic rings in contrast to the concentration-dependent relaxation with ATP. In endothelium-denuded aortic rings, ATPP induced contraction, as ATP did, but with a greater potency. alpha, beta-methylene ATP (APCPP 50 microM), a P2x-purinoceptor antagonist, significantly inhibited ATPP- as well as ATP-induced contractions in the endothelium-denuded preparations suggesting that ATPP acts via P2x-purinoceptors. ATPP (10 approximately 100 microM) relaxed precontracted aortic rings with an intact endothelium in a concentration-dependent manner. This effect of ATPP was 3.7 fold less potent than that of ATP. However, after P2x-purinoceptor blockade, the effect became identical between the two nucleotides. Reactive blue 2, a selective antagonist of P2x-purinoceptors, significantly attenuated the ATPP-induced relaxation with no change in the ATP-induced relaxation. These results indicated that the rat aortic endothelium contains heterogeneous populations of P2-purinoceptors (possibly P2y and nucleotide receptors). Since ATPP shows dual effects depending upon the vascular tension, it may play a significant role in the physiological regulation of vascular tone.
