Biochemistry adenine nucleotides assistance

[Biostudent]

What two pathways exist to make adenine nucleotides? Why might supplying the compound hypoxanthine to the heart improve function after ischemia?

 

Two pathways may be perhaps

 

De Novo Synthesis of Purine Nucleotides

Purine base salvage (using hypoxanthine-guanine phosphoribosyltransferase (HGPRT))

 

hypoxanthine to the heart I'm really not sure about why this improves the function but I would assume it has something to do with DNA repair or ATP synthesis?

 

This is about as far as I have been able to get (I haven't been taught this so it's making it that much harder)

Any help is appreciated.