Identification of adenosine A2 receptor-cAMP system in human aortic endothelial cells.
The involvement of endothelial adenosine A2 receptor-cAMP system in A2 receptor-mediated vasodilation in human aortic endothelial cells (HAEC) was investigated. Reverse transcription-polymerase chain reaction (RT-PCR) revealed the expression of both A2a and A2b receptors mRNA in HAEC. In HAEC, YT-146 (selective A2 receptor-agonist) produced a dose-dependent increase of cAMP production. This increase was inhibited by theophylline. YT-146 also showed a vasodilatory action in isolated rat aorta. The removal of endothelium significantly attenuated this vasodilatory effect. Our results provide the first evidence for the expression of both subtypes of the A2a and A2b receptors which regulate cAMP production in human endothelial cells. The present results also suggest that A2 receptor-cAMP system was involved in the endothelium-dependent vasodilatory actions and may play important roles in regulating vascular functions of HAEC.
Iwamoto
T
T
Second Department of Internal Medicine, Yokohama City University School of Medicine, Japan.
Umemura
S
S
Toya
Y
Y
Uchibori
T
T
Kogi
K
K
Takagi
N
N
Ishii
M
M
D000109:Acetylcholine / Q000494:pharmacology; D000241:Adenosine / Q000031:analogs & derivatives / Q000494:pharmacology; D000480:Alkynes / Q000494:pharmacology; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D001011:Aorta; D001013:Aorta, Thoracic / Q000187:drug effects / Q000502:physiology*; D001483:Base Sequence; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism*; D017931:DNA Primers; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008969:Molecular Sequence Data; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology*; D010656:Phenylephrine / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018047:Receptors, Purinergic P1 / Q000096:biosynthesis / Q000187:drug effects / Q000378:metabolism*; D013806:Theophylline / Q000494:pharmacology*
D000480:Alkynes; D000959:Antihypertensive Agents; D017931:DNA Primers; D012333:RNA, Messenger; D018047:Receptors, Purinergic P1; D010656:Phenylephrine; C070494:YT 146; D013806:Theophylline; D000242:Cyclic AMP; D000241:Adenosine; D000109:Acetylcholine