EagleBio’s March Promotions


Check Out our Monthly Promotions! 

30% Discount on Select Cardiac Biomarker Assays


BNP Fragment ELISA

NT-proCNP ELISA

NT-proANP ELISA

Endostatin ELISA

Big Endothelin-1 ELISA

Endothelin (1-21) ELISA 


This promotion is good through the end of March just use the code below when ordering. 

PROMOTIONAL CODE: CARD0230 



Related News:

EagleBio Spotlight: Endothelin

EagleBio Spotlight: Natriuretic Peptides

EagleBio Spotlight: ANP

EagleBio Spotlight: CNP

EagleBio Spotlight: BNP

Interesting Study Highlighting Eagle Biosciences’ BNP Fragment ELISA Assay Kit 

EagleBio Spotlight: Endostatin

Eagle Biosciences Introduces Endothelin 1-21 and Big Endothelin-1 ELISA Kit



Related Resources Citing EagleBio Kits:

Stanek, B. et al. “Prognostic evaluation of neurohumoral plasma levels before and during beta-blocker therapy in advanced left ventricular dysfunction” Journal of American Cardiology 2001; 38: 436-442.


Related kits:

Cardiovascular Assay Kits

EagleBio Spotlight: Natriuretic Peptides



What
are Natriuretic peptides?

The natriuretic peptides belong to a family of
structurally similar but genetically different peptide hormones and include atrial, brain, and C type (ANP, BNP, and CNP, respectively). A-type and B-type have primarily have functions in the cardiovascular system and make up the cardiac natriuretic peptides. 
The discovery of this family was a major breakthrough in modern medicine and more specifically, cardiovascular physiology. This finding provided a direct connection between the heart and the kidneys with respect to the regulation of natriuresis.

These natriuretic peptides are modulated through their cognate receptors which are known as the ANP-A (a.k.a. NPR-A, GC-A), ANP-B (a.k.a. NPR-B, GC-B) and ANP-C (a.k.a NPR-C) receptors. ANP and BNP
preferentially bind to a membrane bound guanylyl cyclase (GC) receptor called
GC-A or NPR1, whereas CNP is the physiological ligand for GC-B (NPR2).

All natriuretic peptides are produced as propeptides,
which are then cleaved into the biologically active, C-terminal hormone
and the N-terminal fragment (NT-proANP 1-98, NT-proBNP 1-76 and NT-proCNP). It has been discovered that N-terminal fragments are
much more stable, and circulate in higher amounts than the active hormones. Thus, for these reasons the N-terminal fragments are easier and more reliable for measurement in serum or plasma.

The natriuretic peptides play an important role in the
regulation of cardiovascular and renal homeostasis and in the regulation of
fatty acid metabolism and body weight. In addition, in recent
studies natriuretic peptides have been proven to be valuable biomarkers for cardiac
pathology, including myocardial ischaemia and left ventricular dysfunction, as
well as risk stratification in congestive heart failure (CVD). 

Natriuretic peptides have a wide range of roles and
effects on several biological functions within the body as seen below.


Biological Functions of Natriuretic
peptides:

  • Natriuresis
  • Vasodilation
  • Homeostasis
  • Inhibition of
    aldosterone system
  • Inhibition of
    renin-angiotensin system
  • Inhibition of
    vascular smooth muscle growth (i.e. myocardial, endothelial, smooth
    muscle)
  • Inhibition of
    ADH hormone
  • Inhibition of
    aldosterone hormone

References

  1. Clerico A et al. “Thirty years of the heart as an endocrine organ: physiological role and clinical utility of cardiac natriuretic hormones.” Am J Physiol Heart Circ Physiol 2011; 301: H12-H20.
  2. Doust, Jenny et al. “The Role of BNP Testing in Heart Failure.” American Family Phyisician; 2006 Dec 1;74(11):1893-190.
  3. Lauridsen, Bo K et al. “ProANP Plasma Measurement Predicts All-Cause Mortality in Acutely Hospitalized Patients: A Cohort Study.” BMJ Open 2013;3:e003288 doi:10.1136/bmjopen-2013-003288
  4. Moro, Cedric et al. “Natriuretic Peptides: New Players in Energy Homeostasis.” Diabetes 2009; 12: 2726-2728
  5. Nazario, B et al. “Atrial and Brain Natriuretic Peptides Stimulate the Production and Secretion of C-type Natriuretic Peptide from Bovine Aortic Endothelial Cells.” Journal of Clinical Investigation 1995 Mar; 95(3): 1151–1157.
  6. Schreibe, Donald et al. “Natriuretic Peptides in Congestive Heart Failure.” Medscape 2012: Jan 10.
  7. Suzuki, T et al. “The Role of the Natriuretic Peptides in the Cardiovascular System.” Cardiovascular Research 2001; 51: 489–494.
  8. Stanek, B. et al. “Prognostic evaluation of neurohumoral plasma levels before and during beta-blocker therapy in advanced left ventricular dysfunction” Journal of American Cardiology 2001; 38: 436-442

Related Resources Citing EagleBio Kits:

  1. Stanek, B. et al. “Prognostic evaluation of neurohumoral plasma levels before and during beta-blocker therapy in advanced left ventricular dysfunction” Journal of American Cardiology 2001; 38: 436-442.

Related Kits:

proANP ELISA Assay Kit

BNP Fragment (Nt-proBNP 8-29) ELISA Assay Kit

NT-proCNP ELISA Assay Kit

Cardiovascular Assay Kits


Related News:

EagleBio Spotlight: ANP

EagleBio Spotlight: BNP

EagleBio Spotlight: CNP

Interesting Study Highlighting Eagle Biosciences’ BNP Fragment ELISA Assay Kit 

EagleBio Spotlight: ANP


What
is ANP?

The first
natriuretic peptide was identified in 1983 and named atrial natriuretic peptide
(ANP). ANP is a 28-amino acid polypeptide resulting from the C-terminal end of
the prohormone proANP. It is largely produced in the cardiac atria, and ANP is
quickly secreted in response to atrial stretching. ANP has the following
physiological effects:

  • Increases glomerular
    filtration rate by dilating afferent arterioles
  • Inhibits the collecting ducts from reabsorbing sodium,
    both directly and indirectly (by inhibiting aldosterone secretion)
  • Inhibits release of renin

The renin-angiotensin system and ANP
function antagonistically in the maintenance of fluid/electrolyte balance and
blood pressure.

Normal hearts
secrete extremely small amounts of ANP, but elevated levels are found in
patients with left ventricular (LV) hypertrophy and mitral valve disease.


Biochemical structure of ANP:

ANP is synthesized as a 126 amino acidprecursor protein which is cleaved to produce a
96 aminoacid amino-terminal fragment and a 28 amino acid
carboxyl-terminal fragment. The carboxyl-terminal 28 amino acid fragment is the biologically active peptide and
has shorter half-life than the amino-terminal fragment.



Conserved residues are shaded and the line
within the ring represents the disulfide bond. 


What
is proANP?

ProANP is the prohormone of ANP (ANP is stored as a
126–amino acid prohormone (proANP1–126)). After this prohormone is released it is then cleaved into
 equimolar amounts of the biologically active C-terminal peptide (ANP (99–126)) and the residual N-terminal peptide (NT-proANP (1–98)) in response to atrial wall stretch.

α-ANP has a half-life of 3-4 minutes thus is quickly cleared from circulation. ProANP (1-98) on the other hand, has a significantly longer half-life of 60-120 minutes leading to much higher concentrations in blood as compared to α-ANP. 


Why Measure proANP (1-98)?

Atrial natriuretic peptide (ANP) has an important physiological roles in fluid homeostasis and cardiac pathology. The longer half life of proANP (1-98) offers advantages for measuring  the ANP in the blood over α-ANP due to its lack of sensitivity to the pulsatile secretion of ANP. In fact,proANP (1-98) may provide better insight to the ANP status and its chronic secretion in the blood. Studies have shown that proANP serves as a
valuable and stable marker for several areas of research ranging from sepsis to
predicting and aiding in risk stratification for heart failure.


Diseases/conditions associated with increased ANP levels:

  • Diabetes and Obesity
  • Renal Disease/Renal dysfunction
  • Hypertension
  • Pneumonia
  • Asthma attacks
  • Recent heart attack
  • Heart failure/Cardiac impairment
  • Cardiomyopathy
  • Sepsis
  • Sleep apnea


References:

  1. Haviv, M. et al. “Atrial Natriuretic Peptidein Children with Pneumonia.” Pediatric Pulmonology 40:306–309(2005).
  2. Hoffman et al. “Prognostic Value of Plasma N-Terminal Pro-Brain Natriuretic Peptide in Patients With Severe Sepsis.” Circulation; 2005:112:527-534. 
  3. Lauridsen, Bo K et al. “ProANP Plasma Measurement Predicts All-Cause Mortality in Acutely Hospitalized Patients: A Cohort Study.” BMJ Open 2013;3:e003288 doi:10.1136/bmjopen-2013-003288.
  4. Moro, Cedric et al. “Natriuretic Peptides: New Players in Energy Homeostasis.” Diabetes 2009; 12: 2726-2728. 
  5. Robichaud, A. et al. “Plasma Atrial Natriuretic Peptide During Spontaneous Bronchoconstriction in Asthmatics. Peptides 1995;16(4):653-6.

  6. Suzuki, T et al. “The Role of the Natriuretic Peptides in the Cardiovascular System.” Cardiovascular Research 2001; 51: 489–494. 


Related Resources Citing EagleBio Kits:

  1. Stanek, B. et al. “Prognostic evaluation of neurohumoral plasma levels before and during beta-blocker therapy in advanced left ventricular dysfunction” Journal of American Cardiology 2001; 38: 436-442.


Related Kits:

proANP ELISA Assay Kit

Cardiovascular Assay Kits

Related News:

EagleBio Spotlight: Natriuretic Peptides

EagleBio Spotlight: BNP

EagleBio Spotlight: CNP

Interesting Study Highlighting Eagle Biosciences’ BNP Fragment ELISA Assay Kit