Article date: February 1984
By: M.G. Collis, J.R. Keddie, S.R. Torr in Volume 81, Issue 2, pages 401-407
We investigated the possibility that the positive inotropic effects of the alkylxanthines are due to adenosine receptor blockade.
The potency of 8‐phenyltheophylline, theophylline and enprofylline as adenosine antagonists was assessed in vitro, using the guinea‐pig isolated atrium, and in vivo, using the anaesthetized dog.
The order of potency of the alkylxanthines as antagonists of the negative inotropic response to 2‐chloroadenosine in vitro, and of the hypotensive response to adenosine in vivo was 8‐phenyltheophylline > theophylline > enprofylline.
The order of potency of the alkylxanthines as positive inotropic and chronotropic agents in the anaesthetized dog was enprofylline > theophylline > 8‐phenyltheophylline.
The results of this study indicate that the inotropic effects of the alkylxanthines in the anaesthetized dog are not due to adenosine receptor blockade.
We investigated the possibility that the positive inotropic effects of the alkylxanthines are due to adenosine receptor blockade.
The potency of 8‐phenyltheophylline, theophylline and enprofylline as adenosine antagonists was assessed in vitro, using the guinea‐pig isolated atrium, and in vivo, using the anaesthetized dog.
The order of potency of the alkylxanthines as antagonists of the negative inotropic response to 2‐chloroadenosine in vitro, and of the hypotensive response to adenosine in vivo was 8‐phenyltheophylline > theophylline > enprofylline.
The order of potency of the alkylxanthines as positive inotropic and chronotropic agents in the anaesthetized dog was enprofylline > theophylline > 8‐phenyltheophylline.
The results of this study indicate that the inotropic effects of the alkylxanthines in the anaesthetized dog are not due to adenosine receptor blockade.
DOI: 10.1111/j.1476-5381.1984.tb10092.x
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