Effects of adrenomedullin on load and myocardial performance in normal and heart-failure dogs.
Myocardial actions of the vasodilator peptide adrenomedullin ( ADM) in the intact animal are unknown. Negative and positive inotropic actions have been reported in ex vivo experiments. Myocardial and load-altering actions of ADM in dogs before and after development of heart failure were studied. With controlled heart rate (atrial pacing) and after beta-blockade, ADM was administered to five normal dogs in doses of 20 ng. kg(-1). min(-1) iv, 100 ng. kg(-1). min(-1) iv, and 200 ng. kg(-1). min(-1) into the left ventricle (LV). LV peak systolic pressure and end-systolic volume decreased with each dose of ADM. End-systolic pressure decreased with the two higher doses. At the highest dose, arterial elastance and the time constant of LV isovolumic relaxation (tau) decreased, and LV end-systolic elastance (E(es)) increased. LV end-diastolic pressure and volume were unchanged. In five additional normal dogs receiving only the highest dose of ADM (200 ng. kg(-1). min(-1) intra-LV), to control for increased heart rate and sympathetic activation observed with the cumulative infusion, ADM produced arterial vasodilation but no change in E(es) or tau. In four dogs with pacing-induced heart failure, ADM (200 ng. kg(-1). min(-1) intra-LV) was without effect on tau, E(es), and systolic or diastolic pressure and volume. In vivo, ADM appears to be a selective arterial dilator without inotropic or lusitropic effects. The vasodilatory actions are attenuated in heart failure.[1]References
- Effects of adrenomedullin on load and myocardial performance in normal and heart-failure dogs. Lainchbury, J.G., Meyer, D.M., Jougasaki, M., Burnett, J.C., Redfield, M.M. Am. J. Physiol. Heart Circ. Physiol. (2000) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg









