Possible evidence for involvement of new subtype of P1-purinoceptors in rat isolated uterus.
1. The effects of adenosine (Ado), 5'-N-ethylcarboxamidoadenosine (NECA), 2-chloro-adenosine, N6-phenylisopropyladenosine (L-PIA and D-PIA) and N6-cyclohexyladenosine (CHA) were examined on the rat isolated uterus. 2. All the analogues except NECA, in a concentration-dependent manner, inhibited electrically induced contractions. 3. 8-Phenyltheophylline (8-PT: P1 antagonist) did not antagonize adenosine and its analogues-induced relaxation. 4. Dipyridamole (Dipy: an adenosine uptake inhibitor) potentiated the relaxations to adenosine but had no significant effect on the relaxations induced by the analogues. 5. The agonist potency order for the relaxation of contractions elicited by direct muscle stimulation was: CHA > L-PIA > 2-chloroadenosine > D-PIA > Ado. 6. The present data may propose the presence of a new subtype of P1-purinoceptor.
Dehpour
A R
AR
Department of Pharmacology, Faculty of Medicine, Tehran University of Medical Sciences, Iran.
Jabbary
M
M
Shadan
F
F
Ghafourifar
P
P
D015762:2-Chloroadenosine / Q000494:pharmacology; D000241:Adenosine / Q000031:analogs & derivatives / Q000494:pharmacology; D019830:Adenosine-5'-(N-ethylcarboxamide); D000818:Animals; D004558:Electric Stimulation; D005260:Female; D066298:In Vitro Techniques; D010660:Phenylisopropyladenosine / Q000494:pharmacology; D051381:Rats; D018047:Receptors, Purinergic P1 / Q000187:drug effects / Q000502:physiology*; D013237:Stereoisomerism; D014590:Uterine Contraction / Q000187:drug effects / Q000502:physiology*
D018047:Receptors, Purinergic P1; D015762:2-Chloroadenosine; D010660:Phenylisopropyladenosine; D019830:Adenosine-5'-(N-ethylcarboxamide); C027513:N(6)-cyclohexyladenosine; D000241:Adenosine