ATRIAL NATRIURETIC PEPTIDE BEHAVIOUR AND MYOCYTE

SUSANA CAVALLERO; GERMÁN E. GONZÁLEZ; ANA M. PUYÓ; MARÍA I. ROSÓN; SUSANA PÉREZ; CELINA MORALES; CECILIA M. HERTIG; RICARDO J. GELPI; BELISARIO E. FERNÁNDEZ

J Hypertension

Lippincott Williams & Wilkins

Lugar: London; Año: 2006

0263-6352

Objective: To investigate cardiomyocyte hypertrophy and hormonal profile in cardiac hypertrophy resulting from sequentially applied overloads. Methods: We studied Sprague-Dawley rats with renovascular hypertension (RV), where pressure overload predominates, or DOCA-salt (DS), where volume overload predominates, at 2 and 4 weeks of treatment, and the combination of both models in inverse sequence: RV 2 weeks/DS 2 weeks (RV2/DS2) and DS 2 weeks/RV 2 weeks (DS2/RV2), and their sham controls. Results: Blood pressure and cardiomyocyte diameter increased to a similar extent in RV and DS at 2 and 4 weeks and in combined models. Cardiomyocyte length remarkably increased in DS4 group. Circulating ANP was elevated in all hypertensive groups after 2 and 4 weeks. RV2/DS2 group showed similar plasma ANP levels to RV4, but DS2/RV2 exhibited a 3-fold increase in ANP levels (p<0.001 vs. Sh4, DS2 y DS4). Atrial ANP mRNA remained unchanged in all groups. DS treatment alone or in combination with RV increased left ventricular ANP mRNA, meanwhile only RV treatment increased left ventricular BNP mRNA. Ventricular ANP expression levels, but not circulating ANP, correlated with both cardiomyocyte diameter (r= 0.859, p<0.01) and length (r= 0.848, p<0.01). Renal expression of NPR-C was unchanged in RV4 but decreased to a similar extent in DS4 group and both combined treatments. Conclusion: Morphometric patterns seem to be more related to the paracrine function of the heart than to the secretion of ANP and the endocrine function. Plasma ANP in DS2/RV2 group could indicate a different evolution of the remodelling process. ANP expression seems to be a more sensitive marker for volume than pressure overload.