Atrial Natriuretic Peptide: Structure, Function, and Physiological Effects:A Narrative Review

Figures

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  Fig. (1). Cleavage of pre-proANP and proANP/ANP structure. The 151amino acid pre-proANP, with a signal peptide with sequence rich hydrophobic residues, is cleaved by a signal peptidase to produce a 126 amino acid proANP [2]. The proANP is cleaved by corin, a transmembrane protease, to produce the 28 amino acid active ANP and an N-terminal peptide. A disulfide bridge is present between the two cysteine residues [position 7 and 23] in active ANP [6, 17]. (A higher resolution / colour version of this figure is available in the electronic copy of the article).

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  Fig. (2). Downstream effects of ANP and cGMP. ANP binds to natriuretic peptide receptor A, a guanylyl cyclase receptor, converting GTP into cGMP. Then cGMP induces effects, such as vasodilation and increased natriuresis, to reduce systemic blood pressure. cGMP may also alter the effects of RAAS and the sympathetic nervous system [10, 11]. (A higher resolution / colour version of this figure is available in the electronic copy of the article).

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  Fig. (3). Channels present in parts of the nephron [ 95 ]. In the PCT, the Na+/H+ ATPase is inhibited by ANP [37]. The second messenger cGMP induces the production of NO, inhibiting NKCC in the TAL LOH [40, 41]. The collecting duct has the ENaC channel; ANP may decrease the translocation of these channels and prevent sodium reabsorption [42]. Principal cells in the collecting duct exhibit decreased AQP2 expression on the apical membrane in the presence of ANP after ADH administration [43, 44]. (A higher resolution / colour version of this figure is available in the electronic copy of the article).