Chamber-dependent circadian expression of cardiac natriuretic peptides

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) have important local functions within the myocardium, where they protect against accelerated fibrosis. As circadian expression of cardiac natriuretic peptides could be of importance in local cardiac protection against disease, we examined the diurnal changes of the mRNAs encoding ANP, BNP, and their common receptor NPR-A in atrial and ventricular myocardium. Forty eight mice were killed at the following ZT times: 4, 8, 12, 16, 20, and 24, where ZT designates Zeitgeber; ZT 0 corresponds to lights ON and ZT 12 corresponds to lights OFF. Eight animals (4 males and 4 females) were included at each time point. Another 48 animals were killed during the second cycle of dark/dark (designated Circadian Time or CT: CT 4, CT 8, CT 12, CT 16, CT 20, and CT 24). The cellular contents of the clock genes Per1 and Bmal1 as well as ANP, BNP, and their common receptor (NPR-A) were determined using RT-PCR. Per1 and Bmal1 mRNA contents oscillated in antiphase in both atrial and ventricular regions, where Bmal1 mRNA peaked 12h out of phase relative to Per1 mRNA. ANP and NPR-A atrial mRNA contents revealed borderline significant diurnal changes, whereas ventricular BNP mRNA contents exhibited pronounced oscillation during constant darkness with nadir at CT 12 (P
TidsskriftRegulatory Peptides
Udgave nummer1-3
Sider (fra-til)140-5
Antal sider6
StatusUdgivet - 25 feb. 2010

ID: 34114813