Effect of adrenomedulin on myocardial distensibility.

• Type: Summary of Presentation in an International Conference
• Date: 2007

Authors

Fontes-Sousa AP (Author) Other; Pires AL (Author) FMUP; Leite-Moreira AF (Author) FMUP

Conference proceedings International

Title: European Journal of Heart Failure

Initial page: 143

Heart Failure 2007

Hamburgo, Alemanha, 09 a 12 de Junho de 2007

Scientific classification

FOS: Medical and Health sciences > Other medical sciences

Other information

Resumo (PT): Adrenomedullin (AM) is a potent vasodilator peptide that was originally isolated from pheochromocytoma tissue. Different studies reported that plasma AM levels are increased in the context of several disease processes, such as heart failure and hypertension. In addition to its vasodilatory properties, AM produces disparate biological effects in the cardiovascular system. In the current study, we investigated the, yet unknown, acute effects ofAMon the diastolic properties of the myocardium. Effects of increasing concentrations of AM (10-10 to 10-6M) were evaluated in isolated right papillary muscles (n=10) from male New Zealand White rabbits (Krebs-Ringer: 1,8mM CaCl2, 35°C). Reported parameters include: active tension (AT; mN/mm2), passiv±e tension (PT; mN/mm2) and muscle length (L; L/Lmax). Only significant results (means±SEM, p<0.05) are given, expressed as % change from baseline. AM induced a significant negative inotropic effect, with the highest concentration decreasing the AT by 17,8±5,4%. It also promoted a concentrationdependent increase in resting muscle length up to 1,009±0,003 L/Lmax at the highest concentration. Correcting muscle length to its initial value resulted in a 25.0±5.9% decrease of RT, indicating decreased muscle stiffness. In conclusion, the present study showed that AM significantly decreased RT, indicating a decrease in myocardial stiffness. This effect is a potentially powerful physiologic mechanism, as it may allow the heart to reach the same diastolic volume with up to 25% lower filling pressures. Furthermore, as the plasmatic levels of AM are increased in heart failure, this is a novel finding with potential pathophysiologic and therapeutic implications in heart failure, which deserves further investigation.

Language: English

Type (Professor's evaluation): Scientific

Notes: Heart Failure 2007, published in journal, European Journal of Heart Failure Supplements. 2007; 6(Suppl.1):143.