Cardiomyocytes - Tissue Functioning and Remodeling in the Circulatory and Ventilatory Systems - page 233

Tabl e 5. 6. Prohormone and active members of the natriuretic peptide category. Prohormones
are formed upon cleavage by peptidases of preprohormones. Preprohormone of each natriuretic
peptide is encoded by a distinct gene such as proproANP, or prepronatriodilatin, by the NPPA gene.
Natriuretic peptides have an antihypertensive function, as they lower plasma renin and aldosterone
concentrations and stimulate natriuresis and diuresis, hence reducing the blood volume, in
addition to a vasorelaxant activity. Cardiac natriuretic peptides operate as counter-regulators of
sympatheticoadrenal and neurohormonal axes. In addition, they can have an anti-inflammatory
and pro-apoptotic action in endothelial cells.

Type Name

ANP 1 −− 126 ANP prohormone (proANP)
C-terminal active forms
ANP 99 −− 126 ) ANP, atriopeptin, cardiodilatin
ANP 95 −− 126 ) Urodilatin
Active fragments of inactive proANP 1 −− 98 N-terminus
ANP 1 −− 30 Long-acting natriuretic peptide

ANP 31 −− 67 Vessel dilator

ANP 79 −− 98 Kaliuretic peptide

BNP 1 −− 108 BNP prohormone (proBNP)

BNP 77 −− 108 BNP

CNP 1 −− 103 CNP prohormone (proCNP)

CNP 51 −− 103 CNP 53

CNP 82 − 103 CNP 22

DNP 1 −− 38 DNP

Tabl e 5. 7. Site of synthesis of cardiac natriuretic peptides.

Type Gene Number of Producing cells Secretion stimulus

amino acids

ANP NPPA 28 Atriomyocyte Stretch

Sympathetic stimulation
(

-adrenoceptor)
Hypernatremia
Angiotensin-2, endothelin

β

BNP NPPB 32 Ventriculomyocyte Tension

CNP NPPC 22 Endothelial cells Shear

Central nervous system

DNP NPPD 38 Atriomyocyte Stretch

smooth muscle clls in the kidney [ 403 ]. Then, cGMP-dependent protein kinase-G
inhibits Na + reabsorption via ENaC channel. Relaxation of renal arterial smooth
myocytes results from a decrease in intracellular Ca 2 + concentration.