Sodium nitroprusside pharmacoangiography: arteriographic enhancement by local vasodilation

Sodium nitroprusside (SNP) was injected intra-arterially into the right femoral artery of five dogs, to promote arteriographic enhancement with minimal systemic effects. Injection of 3 microgram/Kg SNP or more, produced tachycardia, hypotension and increased pulsatile arterial blood flow. a 36% pulsatile arterial flow increase, which lasted 25 seconds or less, was the most remarkable systemic change seen after intra-arterial injection of 2.5 microgram/Kg SNP. Small doses were followed by even lesser systemic changes but were ineffective in promoting arteriographic enhancement. Comparison of arteriograms obtained before and after 2.5 microgram/Kg SNP injection showed increased arterial diameter, greater architectural detail and extensive visualization of previously undetected smaller arteries in post-SNP angiograms. Thus, suggesting that 2.5 microgram/Kg was the optimal SNP dose for production of local arterial without remarkable systemic effects. Good results of SNP pharmacoangiography in this experimental series suggest that further research on this topic is warranted.