The protein hormones secreted by the heart muscle cells are called atrial peptides. This presentation gives a detailed information about the structure, production and pharmacological effects of atrial natriuretic peptides.

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3. INTRODUCTION
• They are protein hormones secreted by heart muscle
cells.
• Powerful vasodilator.
• Involved in homeostatic control of body water, Na+,K+
and fat.
• Released by atrial myocytes in response to high blood
pressure.
• ANP acts to reduce water, Na+, adipose loads on
circulatory system, thereby reducing blood pressure.
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4. STRUCTURE
•ANP is a 28 amino acid peptide with a 17 amino acid ring in the middle of the
molecule.
•The ring is formed by a disulfide bond between 2 cysteine residues at positions
7 and 23.
•ANP is closely related to BNP and CNP which all share the same amino acid
ring.
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5. PRODUCTION
• Produced, stored and released by cardiac myocytes of atria of heart.
•Released in response to atrial stretch and a variety of other signals induced by
hypervolemia, exercise or caloric restriction.
• Expressed in ventricle in response to stress induced by increased afterload or
injury.
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6. SECRETED IN RESPONSE TO-
Atrial distension
Sympathetic stimulation of β adrenoceptors
Raised sodium concentration
Angiotensin-II
Endothelin, a powerful vasoconstrictor
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7. RECEPTORS
GC-A
• Also known as NPRA/ANPA or NPR1
GC-B
• Also known as NPRB/ANPB or NPR2
Natriuretic peptide clearance receptor (NPRC)
• ANPC or NPR3
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8. PHARMACOLOGICAL EFFECTS
RECEPTOR
BINDING
REDUCES
BLOOD
VOLUME
REDUCES
CARDIAC
OUTPUT AND
BP
• Lipolysis is increased and renal sodium reabsorption is decreased
• Overall effect is to counter the increase in blood pressure and volume caused by
renin- angiotensin system
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9. 1. RENAL
•Dilates afferent glomerular arteriole.
•Constricts efferent glomerular arteriole.
•Increases pressure in glomerular capillaries, increasing GFR,
resulting in greater excretion of sodium and water.
•Decreases sodium reabsorption in DCT and collecting duct
•Inhibits renin secretion.
•Reduces aldosterone secretion.
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10. 2. VASCULAR
Relaxes vascular smooth muscle in arterioles and venules by-
1. Membrane receptor mediated elevation of vascular smooth
muscle cGMP
2. Inhibition of effect of catecholamine
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11. •Increases release of free fatty acids from adipose tissue
•Plasma concentration of glycerol and non esterified fatty acids are
increased by IV infusion of ANP
3. ADIPOSE TISSUE
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12. • Inhibits maladaptive cardiac hypertrophy
• Mice lacking cardiac NPRA develop increased
cardiac mass and severe fibrosis and die
suddenly
4. CARDIAC
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13. • Reduces aldosterone secretion by the zona
glomerulosa of adrenal cortex.
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5. ADRENAL

14. • ANP and related peptides are used as
biomarkers for cardiovascular diseases such
as stroke, MI, coronary artery disease and
heart failure.
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BIOMARKER

15. • Recombinant human ANP has been approved
in Japan to treat patients with heart failure.
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THERAPEUTIC USE

16. • Regulation of effects of ANP is achieved
through gradual degradation of peptide by
the enzyme neutral endopeptidase (NEP).
• NEP inhibitors have been developed but not
yet been licensed. They maybe clinically
useful in treating congestive heart failure.
DEGRADATION
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17. • www.wikipedia.com
• www.google.com
• www.ncbi.nlm.nih.gov
• www.cvpharmacology.com
• www.sciencedirect.com
REFERENCES
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