Processing of long-acting natriuretic peptide and vessel dilator in human plasma and serum

High performance-gel permeation chromatography (HP-GPC) evaluation of human plasma and serum incubated at 37 degrees C up to 24 h after the addition of long-acting natriuretic peptide (LANP) revealed a 25% decrease in LANP's peak at 2 h followed by an increase in plasma without EDTA at 8 h (p < 0.001). Vessel dilator's HP-GPC peak did not decrease until after 8 h of incubation. These findings help explain the prolonged half-lives and 6-24 higher plasma concentrations of vessel dilator and LANP compared to atrial natriuretic factor and kaliuretic peptide, which are completely degraded in plasma within 2 h.