Method of determining viability of tissue

Abstract

A method and composition for determining the viability of tissue in a region of an organism having a vascular circulatory system that supplies blood to said region including the steps of dilating said vascular circulation system by introducing adenosine or an adenosine agonist into said vascular circulation system in order to increase the flow of blood into said region; introducing a blood flow marking medium into said region; alleviating the non-dilating effects of adenosine or said adenosine agonist by introducing an A.sub.1 adenosine receptor antagonist into said vascular circulatory system; and determining the amount of marking medium in said region. A composition is disclosed which includes the combination of adenosine or an adenosine agonist in combination with an A.sub.1 adenosine receptor which may be: ##STR1## wherein R.sub.1 is hydrogen or R.sub.2 ; R.sub.2 is selected from the group consisting of endo-2-norbornyl or cyclopentyl; R.sub.3 is selected from the group consisting of hydrogen, halogen, amine, carboxy, alkyl radicals having 1 to 10 carbon atoms, cycloalkyl radicals having from 3 to 8, preferably 5 to 6, ring carbon atoms, thio, sulfonate, sulfonamide, sulfon, sulfoxamide, phenyl, alkyl-substituted amine, and cycloalkyl substituted amine; R.sub.4 is selected from the group consisting of benzyl, phenyl, and alkyl groups comprising from 1 to 4 carbon atoms, wherein said alkyl group can be substituted with oxygen, for instance ethers and alcohols; and R.sub.5 is selected from the group consisting of hydrogen; hydroxy; sulfonate; halogen; alkoxy and cycloalkoxy groups comprising 1 to 6 carbon atoms.