Cardiovascular and metabolic actions of an adenosine analogue (2'3'-o-methoxy-ethyliden-adenosine-5'-ethylcarboxamide) in the conscious dog.

The haemodynamic and metabolic actions of 2'3'-o-methoxyethyliden-adenosine-5'-ethylcarboxamide (744-98) were investigated in conscious dogs after i.v. and oral administration. 744-98 led to a marked dose-dependent increase in coronary blood flow, together with a slight increase in renal blood flow. In the standing position high doses of the drug revealed an adenosine-like negative chronotropic action, together with marked hypotension. Metabolic effects were observed with the higher coronary-active doses only. The increase in arterial glucose and decrease in free fatty acid levels are considered to be caused by a glucagon-releasing and adenosine-like action of 744-98. The haemodynamic and metabolic changes were observed both after i.v. and oral administration, showing a ratio of approximately 3:1 in favour of the parenteral route.