Adenine attenuates the Ca(2+) contraction-signaling pathway via adenine receptor-mediated signaling in rat vascular smooth muscle cells.
Our previous study demonstrated that adenine (6-amino-6H-purine) relaxed contracted rat aorta rings in an endothelial-independent manner. Although adenine receptors (AdeRs) are expressed in diverse tissues, aortic AdeR expression has not been ascertained. Thus, the aims of this study were to clarify the expression of AdeR in rat vascular smooth muscle cells (VSMCs) and to investigate the adenine-induced vasorelaxation mechanism(s). VSMCs were isolated from 8-week-old male Wistar-Kyoto rats and used in this study. Phosphorylation of myosin light chain (p-MLC) was measured by western blot. AdeR mRNA was detected by RT-PCR. Intracellular Ca(2+) concentration ([Ca(2+)]i) was measured by using Fura-2/AM. Vasorelaxant adenine (10-100 μM) significantly reduced p-MLC by angiotensin II (Ang II, 10 μM) in VSMCs (P < 0.05). We confirmed the expression of aortic AdeR mRNA and the activation of PKA in VSMCs through stimulation of AdeR by adenine by ELISA. Intracellular Ca(2+) concentration ([Ca(2+)]i) measurement demonstrated that adenine inhibits Ang II- and m-3M3FBS (PLC agonist)-induced [Ca(2+)]i elevation. In AdeR-knockdown VSMCs, PKA activation and p-MLC reduction by adenine were completely abolished. These results firstly demonstrated that vasorelaxant adenine can suppress Ca(2+) contraction signaling pathways via aortic AdeR/PKA activation in VSMCs.
Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School of Kyushu University, 6-10-1 Hakozaki, Fukuoka, Higashi-ku, 812-8581, Japan.
Toshihiko
T
Fukuda
Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School of Kyushu University, 6-10-1 Hakozaki, Fukuoka, Higashi-ku, 812-8581, Japan.
Takahiro
T
Kuroda
Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School of Kyushu University, 6-10-1 Hakozaki, Fukuoka, Higashi-ku, 812-8581, Japan.
Miki
M
Kono
Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School of Kyushu University, 6-10-1 Hakozaki, Fukuoka, Higashi-ku, 812-8581, Japan.
Mai
M
Hyoguchi
Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School of Kyushu University, 6-10-1 Hakozaki, Fukuoka, Higashi-ku, 812-8581, Japan.
Satoshi
S
Tajiri
Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School of Kyushu University, 6-10-1 Hakozaki, Fukuoka, Higashi-ku, 812-8581, Japan.
Mitsuru
M
Tanaka
Department of Food Science, University of Guelph, Guelph, ON, N1G2W1, Canada.
Yoshinori
Y
Mine
Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School of Kyushu University, 6-10-1 Hakozaki, Fukuoka, Higashi-ku, 812-8581, Japan. tmatsui@agr.kyushu-u.ac.jp.
Toshiro
T
Matsui
D000225:Adenine / Q000494:pharmacology*; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D056966:Excitation Contraction Coupling / Q000187:drug effects*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000187:drug effects* / Q000378:metabolism; D018994:Myosin Light Chains / Q000378:metabolism; D010766:Phosphorylation; D058913:Purinergic Agonists / Q000494:pharmacology*; D034622:RNA Interference; D011921:Rats, Inbred WKY; D011983:Receptors, Purinergic / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology*
D018994:Myosin Light Chains; D058913:Purinergic Agonists; D011983:Receptors, Purinergic; D014665:Vasodilator Agents; C459899:adenine receptor, rat; D000804:Angiotensin II; D017868:Cyclic AMP-Dependent Protein Kinases; D000225:Adenine
Adenine; Adenine receptor; Ca2+ signaling; Vascular smooth muscle cell; Vasorelaxation