Rate of diadenosine polyphosphate degradation by various guinea pig tissues

High-performance liquid chromatography and colorimetry of inorganic phosphorus show that in the presence of muscle tissues from the guinea pig bladder, seminal duct, small intestine, longitudinal cord of the cecum, and right atrium all diadenosine polyphosphates with a common formula APnA (n=2–6) are degraded more slowly than ATP. The rate of APnA cleavage is highest in experiments with the small intestinal and right atrial tissues. P2-purine receptor antagonist suramin inhibits degradation of AP3A by right atrial tissue and does not modify degradation of other APnA. Enzymatic stability of endogenous APnA is apparently the principal condition for manifestation of their biological effects.