Effects of adenosine and its derivatives on cultured myocardial cells and detection of adenosine receptors in rat
Abstract
Adenosine and its derivatives 1 nmol.L-1 -0.1 mmol.L-1 elicited negative chronotropic effect on cultured rat myocardial cells. The respective IC50 were: L-PIA 85 +/- 10 greater than NECA 160 +/- 64 greater than adenosine 361 +/- 41 nmol.L-1. The negative chronotropic effect was antagonized by IBMX. [3H]Adenosine bound to myocardial cells of rat in a saturable way with a Kd of 238 nmol.L-1 and a Bmax of 7.6 pmol/10(8) cells. The binding of [3H]adenosine was competitively antagonized by adenosine, L-PIA, NECA, and IBMX. These results indicated the existence of adenosine receptor in rat myocardial cells.
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