Long-term effects of ribose on adenine nucleotide metabolism in isoproterenol-stimulated hearts.
1. Among the precursor substances tested 1-14C-glycine is the most suitable for measuring rates of AN biosynthesis in rat hearts in vivo. 2. Continuous i.v. infusion of ribose for 24 hours stimulates AN biosynthesis in normal hearts and amplifies the enhancement of this process in hearts of isoproterenol-treated rats. The isoproterenol-induced decline of myocardial ATP is prevented by long-term application of ribose. 3. Elevation of the available PRPP pool mainly mediated by ribose and release of feedback inhibition of PRPP amidotransferase activity by the isoproterenol-induced ATP decline appear to be the optimal conditions required for maximal stimulation of myocardial AN biosynthesis.
D000227:Adenine Nucleotides / Q000378:metabolism*; D000818:Animals; D005260:Female; D005561:Formates / Q000378:metabolism; D005998:Glycine / Q000378:metabolism; D006321:Heart / Q000187:drug effects*; D007545:Isoproterenol / Q000494:pharmacology*; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D012266:Ribose / Q000494:pharmacology*
D000227:Adenine Nucleotides; D005561:Formates; D012266:Ribose; D007545:Isoproterenol; D005998:Glycine