Diagnostic utility of a human N-terminal proANP assay for cardiac assessment in cynomolgus monkeys

Atrial natriuretic peptide (ANP) is a well-established biomarker of cardiac disease; however, its clinical utility in cynomolgus monkeys is limited by its short half-life and the requirement for immediate proteolysis inhibition. This study validated a human NT-proANP assay in cynomolgus monkeys to facilitate the use of archived samples for cardiac assessment. We performed in silico amino acid sequence homology analysis and validated the assay using monkey serum and plasma. Stability under various storage conditions was also evaluated. The amino acid sequence of NT-proANP showed high conservation between humans and cynomolgus monkeys. The human NT-proANP assay demonstrated good cross-reactivity and a significant positive correlation with mature ANP levels (R2=0.60). Furthermore, NT-proANP remained detectable for up to 6 h post-collection at room temperature, although a gradual decline was observed. These findings indicate that NT-proANP is a highly useful surrogate marker for ANP in cynomolgus monkeys. This validation expands the potential for retrospective analysis using stored samples, thereby enhancing the value of non-human primate models in cardiovascular research.