natriuretic-peptide--c-type and Edema

The natriuretic peptide system, which comprises at least four related proteins: atrial natriuretic peptide; brain natriuretic peptide; C-type natriuretic peptide; and urodilatin, exerts important influences on central and renal hemodynamics and renal sodium excretion. Recent studies have examined the role of these peptides in the pathophysiology of edema formation in congestive heart failure, cirrhosis, and nephrotic syndrome and have explored the therapeutic value of manipulating their metabolic pathways. One striking feature appears common to all three states ie, a blunted response to the natriuretic effect of atrial natriuretic peptide, which becomes particularly severe in the late stages of each disease. However, whereas in congestive heart failure and cirrhosis the main mechanism responsible is enhanced proximal tubular reabsorption of sodium resulting in reduced distal sodium delivery to the major site of atrial natriuretic peptide action, in nephrotic syndrome a biochemical defect in the cellular response to atrial natriuretic peptide within the kidney is a more likely explanation. Most information regarding the efficacy of therapies that alter the metabolism or the local action of atrial natriuretic peptide pertain to congestive heart failure. However, continued investigation in this area may ultimately lead to interventions that play a valuable role in the future management of all three edematous states.

Topics: Atrial Natriuretic Factor; Diuretics; Edema; Humans; Natriuresis; Natriuretic Peptide, Brain; Natriuretic Peptide, C-Type; Nerve Tissue Proteins; Peptide Fragments; Peptides; Proteins

In this study we characterise the ability of a C-type natriuretic peptide from platypus (Ornithorhynchus anatinus) venom (ovCNP-39) to relax the rat uterus in vitro and we investigate the possibility that ovCNP-39 contributes to the acute effects of envenomation, which include oedema, pain and erythema. We have found that both ovCNP-39 and the endogenous C-type natriuretic peptide, CNP-22, produce oedema in the rat paw and release histamine from rat peritoneal mast cells. Two synthetic peptides, ovCNP-39(1-17) and ovCNP-39(18-39), corresponding to the N- and C-termini, respectively, are equipotent histamine releasers, suggesting that ovCNP-39 and other natriuretic peptides do not act through conventional natriuretic peptide receptors on mast cells.

Topics: Amino Acid Sequence; Animals; Edema; Female; Histamine Release; Intercellular Signaling Peptides and Proteins; Mast Cells; Molecular Sequence Data; Muscle Relaxation; Natriuretic Peptide, C-Type; Peptides; Platypus; Proteins; Rats; Rats, Wistar; Sequence Homology, Amino Acid; Uterus; Venoms