Two new hormones: Prohormone atrial natriuretic peptides 1–30 and 31–67 circulate in man

Atrial natriuretic peptide(31-67) inhibits Na+ transport in rabbit inner medullary collecting duct cells. Role of prostaglandin E2.

“…Because this carboxy-terminal product was readily detectable and exhibited nearly all of the actions of atrial extracts, virtually all subsequent studies focused on the actions of ANP("-126). However, early studies also showed that intact ANP(-126) exhibits biological activity (5 (8,9). This circulating peptide coeluted with authentic synthetic ANP31-67 on reverse phase HPLC, and was shown by gel filtration to have a molecular mass of 4,000, similar to that of authentic ANP31-67 (9).…”

“…They further demonstrated that, like ANPg9 126, this peptide circulates at increased concentrations after HOWL, and in patients with congestive heart failure (8-10). Importantly, this peptide achieves higher plasma levels and exhibits a longer half-life than ANP99-,26 (8)(9)(10) Little is known of the mechanism by which ANP(31-67) exerts its renal actions. Our results show that unlike ANP(99126), which inhibits Na+ entry through the amiloride-sensitive Na+ channel (14,15), ANP(31-7) is a potent inhibitor of This mechanism of action distinguishes ANP31-67 from ANP99-,26 because the binding ofthe latter to its receptor stimulates cGMP accumulation which in turn reduces Na' entry via the amiloride-sensitive cation channel (12,14,15,23,24).…”

“…Antibodies raised against synthetic ANP(31-67) and specific for this peptide identified a circulating peptide of molecular weight similar to that of synthetic ANP(31-67) (molecular mass -4,000 D). This circulating peptide coeluted with synthetic ANP(31-67) on reverse phase HPLC (8,9). Furthermore, this same peptide circulates at a concentration greater than ten times that of ANP("-126), and, as with ANP(99126), the concentration of the peptide increases in the setting of increased right atrial pressure (e.g.,…”

“…More recent evidence suggests that a fragment ofANP(1 98), ANP(31-67), also circulates in plasma (8,9). Antibodies raised against synthetic ANP(31-67) and specific for this peptide identified a circulating peptide of molecular weight similar to that of synthetic ANP(31-67) (molecular mass -4,000 D).…”

Vessel Dilator Enhances Sodium and Water Excretion and Has Beneficial Hemodynamic Effects in Persons With Congestive Heart Failure

“…Subjects with a creatinine level Ͼ1.5 mg/dL were excluded because vessel dilator increases in the circulation of humans with renal failure. 7,8 Likewise, vessel dilator increases in the circulation of persons with ascites, 9,10 so these subjects were excluded from the present study. None of the patients' prescribed medications were taken the day of the study.…”