Presence of Dendroaspis natriuretic peptide-like immunoreactivity in humanplasma and its increase during human heart failure

Objective: To determine whether Dendroaspis natriuretic peptide (DNP), a no vel peptide isolated from the venom of the Dendroaspis angusticeps snake th at contains a 17-amino acid disulfide ring structure similar to that in atr ial, brain, and C-type natriuretic peptides, is present in normal human pla sma and myocardium and whether, like the other natriuretic peptides, DNP-li ke immunoreactivity (DNP-LI) is activated in human congestive heart failure (CHF). Material and Methods: Circulating DNP-LI was assessed in 19 normal human su bjects and 19 patients with CHF (New York Heart Association class III or IV ) with a specific and sensitive radioimmunoassay for DNP with no cross-reac tivity with the other natriuretic peptides, Immunohistochemical studies tha t used polyclonal rabbit anti-DNP antiserum were performed on human atrial myocardial tissue obtained from four patients with endstage CHF who were un dergoing cardiac transplantation and from three donor hearts at the time of transplantation. Results: We report that DNP-LI circulates in normal human plasma and is pre sent in the normal atrial myocardium, In addition, DNP-LI Is increased in t he plasma of patients with CHF, Conclusion: This study demonstrates, for the first time, the presence of a DNP-like peptide in normal human plasma and in the atrial myocardium. Addit ionally, these studies demonstrate increased plasma DNP-LI in human CHF. Th ese results support the possible existence of an additional new natriuretic peptide in humans, which may have a role in the neurohumoral activation th at characterizes human CHF.