Premium
The effect of adenyl compounds on the rat heart
Author(s) -
Burnstock Geoffrey,
Meghji Parviz
Publication year - 1983
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1983.tb10514.x
Subject(s) - adenosine , medicine , inhibitory postsynaptic potential , ehna , endocrinology , purinergic receptor , chemistry , ventricle , biology , adenosine deaminase
1 The effects of adenyl compounds were examined on the rat atrium and ventricle. 2 Adenosine, adenosine 5′‐monophosphate, adenosine 5′‐diphosphate, adenosine 5′‐triphosphate (ATP) and β, γ‐methylene ATP (APPCP) produced negative inotropic effects on the rat atrium. These inhibitory effects were antagonized by 8‐phenyltheophylline (8‐PT), a P 1 ‐purinoceptor antagonist, and potentiated by erythro‐9‐(2‐hydroxy‐3‐nonyl) adenine (EHNA), an adenosine deaminase inhibitor, but were not affected by dipyridamole, which blocks adenosine uptake. 3 α, β‐Methylene ATP (APCPP), which is resistant to degradation, did not produce a similar inhibitory response in the rat atrium. 4 Adenosine did not affect the basal developed force of the rat ventricle nor did it affect the β‐adrenoceptor‐mediated positive inotropic effect. 5 Very high concentrations of ATP (0.1–3 m M ) produced negative inotropic effects in the rat ventricle. APPCP (0.3 m M ) also produced an inhibitory response, which was significantly smaller than that produced by ATP (0.3 m M ). APCPP elicited excitation rather than the expected inhibitory response. 6 The inhibitory effect of ATP in the rat ventricle was not blocked by indomethacin, 8‐PT or atropine. 7 It impossible that the action of ATP in the rat ventricle is mediated via P 2 ‐purinoceptors and that the lack of inhibitory action of APCPP on the rat ventricle is due to the difference in structural conformation between ATP and APCPP. 8 It seems likely that inhibitory P 1 ‐purinoceptors are present in the rat atrium and that the inhibitory responses produced by ATP in the rat ventricle may be mediated via P 2 ‐purinoceptors.