Regulation of purinoceptors in guinea pig pulmonary artery: functional evidences.
In isolated guinea pig pulmonary arteries (precontracted with 1 microM noradrenaline) N6-cyclopentyladenosine (CPA), a selective A1 adenosine receptor agonist, exerted a concentration-dependent contraction, whereas 5'-N-ethylcarboxamidoadenosine (NECA), a non-selective A1/A2 receptor agonist, in the presence of DPCPX (a highly selective A1 receptor antagonist), produced a concentration-related rapid relaxation. Pulmonary arteries obtained from guinea pigs treated with aminophylline (APH) or 8-phenyltheophylline (8-PT) for 10 consecutive days, displayed more pronounced contraction in response to CPA compared to those of solvent-treated animals. Relaxant action of NECA was, however, attenuated in arteries prepared from methylxanthine-treated guinea pigs. Opposite changes were found in vascular tissues excised from chronically dipyridamole(DP)-treated guinea pigs.
Szentmiklósi
A J
AJ
Department of Pharmacology, University Medical School of Debrecen, Hungary.
Ujfalusi
A
A
Cseppentö
A
A
Antal
K
K
Kovács
P
P
Szabó
J Z
JZ
D000241:Adenosine / Q000031:analogs & derivatives / Q000494:pharmacology; D019830:Adenosine-5'-(N-ethylcarboxamide); D000818:Animals; D005260:Female; D006168:Guinea Pigs; D011651:Pulmonary Artery / Q000187:drug effects / Q000378:metabolism*; D058906:Purinergic P1 Receptor Agonists; D058915:Purinergic P1 Receptor Antagonists; D011983:Receptors, Purinergic / Q000378:metabolism*; D014661:Vasoconstriction; D014664:Vasodilation; D014970:Xanthines / Q000494:pharmacology
D058906:Purinergic P1 Receptor Agonists; D058915:Purinergic P1 Receptor Antagonists; D011983:Receptors, Purinergic; D014970:Xanthines; D019830:Adenosine-5'-(N-ethylcarboxamide); C048599:N(6)-cyclopentyladenosine; C051360:1,3-dipropyl-8-cyclopentylxanthine; D000241:Adenosine