Diuretic and natriuretic polypeptides

Abstract

This document provides diuretic and natriuretic polypeptides. For example, this document provides polypeptides having diuretic and/or natriuretic activities. In some cases, a polypeptide provided herein can have diuretic and natriuretic activities, while lacking the ability to lower blood pressure. This document also provides methods and materials for inducing diuretic and/or natriuretic activities within a mammal.

What is claimed is: 
     
         1 . A method for treating a mammal having a renal dysfunction, wherein said method comprises administering, to said mammal, a polypeptide between 45 and 65 amino acid residues in length, wherein said polypeptide comprises a first amino acid sequence:
 (a) set forth in SEQ ID NO:1 or   (b) that aligns to the sequence set forth in SEQ ID NO:1 with five or less amino acid deletions, substitutions, or combinations thereof, and   wherein said polypeptide comprises a second amino acid sequence:   (a) set forth in SEQ ID NO:2 or   (b) that aligns to the sequence set forth in SEQ ID NO:2 with (i) five or less amino acid additions, substitutions, or combinations thereof provided that said addition or substitution does not result in the presence of a cysteine residue or (ii) fifteen or less amino acid deletions, and   wherein said administering is under conditions wherein the severity of a symptom of said renal dysfunction is reduced.   
     
     
         2 . The method of  claim 1 , wherein said mammal is a human. 
     
     
         3 . The method of  claim 1 , wherein said renal dysfunction comprises renal failure. 
     
     
         4 . The method of  claim 1 , wherein said renal dysfunction comprises renal failure accompanied with congestive heart failure. 
     
     
         5 . The method of  claim 1 , wherein said polypeptide is administered intravenously, orally, or intranasally. 
     
     
         6 . The method of  claim 1 , wherein said polypeptide is administered in a slow release formulation. 
     
     
         7 . The method of  claim 1 , wherein said polypeptide is between 37 and 47 amino acid residues in length and comprises an amino acid sequence set forth in SEQ ID NO:1. 
     
     
         8 . The method of  claim 1 , wherein said polypeptide is between 37 and 47 amino acid residues in length and comprises an amino acid sequence that aligns to the sequence set forth in SEQ ID NO:1 with five or less amino acid additions, deletions, substitutions, or combinations thereof. 
     
     
         9 . The method of  claim 1 , wherein said polypeptide is between 45 and 65 amino acid residues in length and comprises (i) a first amino acid sequence set forth in SEQ ID NO:1 and (ii) a second amino acid sequence set forth in SEQ ID NO:2. 
     
     
         10 . The method of  claim 1 , wherein said symptom comprises an abnormal serum creatinine level, urine flow, renin level, glomerular filtration rate, urinary cGMP excretion rate, urinary ANP excretion rate, urinary BNP excretion rate, cardiac output, systemic vascular resistance, or aldosterone level. 
     
     
         11 . The method of  claim 1 , wherein said symptom comprises reduced urine flow, and wherein the urine flow of said mammal increases at least 50% after said administration step. 
     
     
         12 . The method of  claim 1 , wherein said symptom comprises reduced renin level, and wherein the renin level of said mammal increases at least 50% after said administration step. 
     
     
         13 . The method of  claim 1 , wherein said symptom comprises reduced glomerular filtration rate, and wherein the glomerular filtration rate of said mammal increases at least 50% after said administration step. 
     
     
         14 . The method of  claim 1 , wherein said symptom comprises reduced urinary cGMP excretion rate, and wherein the urinary cGMP excretion rate of said mammal increases at least 25% after said administration step. 
     
     
         15 . The method of  claim 1 , wherein said symptom comprises reduced urinary ANP excretion rate, and wherein the urinary ANP excretion rate of said mammal increases at least 25% after said administration step. 
     
     
         16 . The method of  claim 1 , wherein said symptom comprises reduced urinary BNP excretion rate, and wherein the urinary BNP excretion rate of said mammal increases at least 25% after said administration step. 
     
     
         17 . The method of  claim 1 , wherein said symptom comprises increased cardiac output, and wherein the cardiac output of said mammal decreased at least 2% after said administration step. 
     
     
         18 . The method of  claim 1 , wherein said symptom comprises reduced systemic vascular resistance, and wherein the systemic vascular resistance of said mammal increases at least 10% after said administration step. 
     
     
         19 . The method of  claim 1 , wherein said symptom comprises reduced aldosterone level, and wherein the aldosterone level of said mammal increases at least 10% after said administration step.