Adenosine uptake sites in dog heart and brain; interaction with calcium antagonists.
Life Sci
; 35(10): 1109-16, 1984 Sep 03.
Article
em En
| MEDLINE
| ID: mdl-6482650
[3H] Nitrobenzylthioinosine (NBI) binding is characterized in dog heart and brain. Evidence is presented suggesting that [3H]NBI is binding to the adenosine uptake site in both tissues. Physiologic studies in open-chested dogs clearly demonstrate that NBI acts as a coronary vasodilator, consistent with an action at the adenosine uptake site. The binding is reversible, saturable and of high affinity (KD = 0.78 +/- .06 nM for heart and 0.52 +/- .05 nM for brain). Both dipyridamole and hexobendine are high potency inhibitors of [3H]NBI binding in heart and brain while other antihypertensives and vasodilators such as propranolol and nitroglycerin have no effect. The inhibition of [3H]NBI binding observed with dipyridamole was competitive indicating that both agents are acting at the same site. The dihydropyridine calcium antagonists also inhibited binding with a lower potency than the adenosine uptake blockers. Non-dihydropyridine calcium antagonists were much less potent in this regard. The inhibition of [3H]NBI binding observed with the dihydropyridine calcium antagonists was non-competitive suggesting that the calcium channel and adenosine uptake site may be coupled to each other.
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Base de dados:
MEDLINE
Assunto principal:
Tioinosina
/
Encéfalo
/
Bloqueadores dos Canais de Cálcio
/
Adenosina
/
Inosina
/
Miocárdio
Limite:
Animals
Idioma:
En
Ano de publicação:
1984
Tipo de documento:
Article