Intermedin (IMD) is a novel member of the calcitonin/calcitonin gene-related peptide (CGRP). The present study aimed to investigate the cardiovascular effects of IMDs (IMD1-47 and IMD8-47) in rats. Intravenous administration of 150 nmol IMDs continuously decreased mean arterial pressure and inhibited cardiac function. Administration with IMDs decreased left ventricular end-systolic pressure (LVESP) and maximal rate of left-ventricle pressure development (+/-LVdp/dt(max)), and elevated left ventricular end-diastolic pressure (LVEDP). Changes with IMD1-47 treatment were close to that with IMD8-47 (P>0.05). Perfusion of isolated rat hearts in vitro with IMD8-47 (10(-8) and 10(-7)mol/L) resulted in lower LVSP, by 40 and 56% (P<0.01); lower +LVdp/dt (max), by 33 and 47% (P<0.01); lower -LVdp/dt(max), by 25 and 39% (P<0.01); but higher coronary perfusion flow (CPF), by 25% (P<0.05) and 33% (P<0.01), respectively, than controls. However, both IMD8-47 and IMD1-47 (from 10(-13) to 10(-7)mol/L) relaxed preconstricted aortic rings in a dose-dependent manner. Intravenous administration of IMD1-47 and IMD8-47 (10(-7)mol/L) in vivo increased the cyclic adenosine monophosphate (cAMP) content by 68 and 150% (both P<0.01), respectively, in myocardia and 320 and 281% (both P<0.01), respectively, in aortas, compared with controls. Perfusion of isolated hearts with IMD1-47 and IMD8-47 (10(-7)mol/L) enhanced cAMP content by 24% (P<0.05) and 73% (P<0.01), respectively, compared with controls. IMDs inhibited 3H-Leucine incorporation in cardiomyocytes in a concentration-dependent manner. IMD1-47 and IMD8-47 (10(-7) and 10(-8)mol/L) decreased 3H-Leucine incorporation by 12-25% (P<0.01) and 14-18% (P<0.01), respectively. IMD mRNA was detected in cultured neonatal cardiomyocytes and isoproterenol-induced hypertrophic myocardia but not normal myocardia of adult rats. These results suggest that IMD might be a regulatory factor for cardiovascular function and myocardial hypertrophy as a cardiovascular active peptide.
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http://dx.doi.org/10.1016/j.peptides.2005.02.013 | DOI Listing |
J Inherit Metab Dis
January 2025
Department of Internal Medicine, Division of Endocrinology and Metabolic Disease, Maastricht University Medical Center+, Maastricht, The Netherlands.
Hereditary fructose intolerance (HFI) is characterized by liver damage and a secondary defect in N-linked glycosylation due to impairment of mannose phosphate isomerase (MPI). Mannose treatment has been shown to be an effective treatment in a primary defect in MPI (i.e.
View Article and Find Full Text PDFHypertension
December 2024
Vanderbilt Autonomic Dysfunction Center, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN. (L.E.O., A.D., C.A.S., A.G., B.K.B., S.P., I.B.).
Background: The cholinesterase inhibitor pyridostigmine is used to treat orthostatic hypotension by facilitating cholinergic neurotransmission in autonomic ganglia, thereby harnessing residual sympathetic tone to increase blood pressure (BP) preferentially in the upright posture. We hypothesized that less severe autonomic impairment was associated with greater pressor responses to pyridostigmine.
Methods: To identify predictors of pressor response, linear regression analyses between the effect of pyridostigmine on upright BP and markers of autonomic impairment were retrospectively conducted on 38 patients who had a medication trial with pyridostigmine (60 mg single dose).
Circ Res
December 2024
Cardiovascular Research Center, Massachusetts General Hospital, Boston. (C.C., P.X., Z.Y., Y.S., E.S.L., J.D.R., M.C.H.).
Background: Preeclampsia is a hypertensive disorder of pregnancy characterized by systemic endothelial dysfunction. The pathophysiology of preeclampsia remains incompletely understood. This study used human venous endothelial cell (EC) transcriptional profiling to investigate potential novel mechanisms underlying EC dysfunction in preeclampsia.
View Article and Find Full Text PDFCirc Cardiovasc Interv
December 2024
Department of Cardiology, Catharina Hospital, Eindhoven, the Netherlands (D.M.M.D., K. Teeuwen, P.A.L.T., N.H.J.P., F.M.Z.).
Background: In the era of first-generation drug-eluting stents and angiography-guided percutaneous coronary intervention (PCI), the presence of a bifurcation lesion was associated with adverse outcomes after PCI. In contrast, the presence of a bifurcation lesion had no impact on outcomes following coronary artery bypass grafting (CABG). Therefore, the presence of a coronary bifurcation lesion requires special attention when choosing between CABG and PCI.
View Article and Find Full Text PDFStroke
December 2024
Department of Neurosurgery and Interventional Neuroradiology, Xuanwu Hospital, China International Neuroscience Institute, Capital Medical University, National Center for Neurological Disorders, Beijing, China. (L.J.).
Background: Previous trials have failed to demonstrate the benefits of extracranial-intracranial (EC-IC) bypass surgery for patients with carotid or middle cerebral artery occlusion. However, little evidence has focused on the effect of age on prognosis. This study aimed to explore whether EC-IC bypass surgery can provide greater benefits than medical therapy alone in specific age groups.
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