title: Age-related regional differences in cardiac nerve growth factor expression.
abstract: Age has been identified as an independent risk factor for cardiovascular diseases. A shift of the cardiac autonomic nervous system towards an increase in sympathetic tone has been reported in the elderly. Nerve growth factor (NGF) is the main neurotrophic factor that increases the sympathetic activity of the heart. If there is a shift of NGF expression in old compared to young cardiomyocytes and whether there are regional differences in the heart still remain unclear. Therefore, we chose a rat model of different-aged rats (3-4 days = neonatal, 6-8 weeks = young, 20-24 months = old), and isolated cardiomyocytes from the left and the right atrium (LA, RA), as well as from the left and the right ventricle (LV, RV), were used to determine NGF expression on mRNA and protein levels. In neonatal, young, and old rats, NGF amount in LA and RA was significantly lower as compared to LV and RV. In young and old rats, we found significant higher NGF protein levels in LA compared to RA. In addition, both atria showed an increase in NGF expression between age groups neonatal, young, and old. In both ventricles, we observed a significant decrease in NGF expression from neonatal to young rats and a significant increase from young to old rats. The highest NGF amount in LV and RV was observed in neonatal rats. Regarding tyrosine kinase A receptor (TrkA) expression, the main receptor for NGF signaling, both atria showed the largest expression in old rats; while in LV and RV, TrkA was expressed mainly in young rats. These results point to a contribution of nerve growth factors to the change of autonomic tone observed in elderly patients.
authors.affiliation: Department of Cardiology, RWTH Aachen University, Germany. esaygili@ukaachen.de
authors.forename: Erol
authors.initials: E
authors.lastname: Saygili
authors.forename: Rahel
authors.initials: R
authors.lastname: Kluttig
authors.forename: Obaida R
authors.initials: OR
authors.lastname: Rana
authors.forename: Esra
authors.initials: E
authors.lastname: Saygili
authors.forename: Christopher
authors.initials: C
authors.lastname: Gemein
authors.forename: Matthias D
authors.initials: MD
authors.lastname: Zink
authors.forename: Gediminas
authors.initials: G
authors.lastname: Rackauskas
authors.forename: Joachim
authors.initials: J
authors.lastname: Weis
authors.forename: Robert H G
authors.initials: RH
authors.lastname: Schwinger
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Marx
authors.forename: Patrick
authors.initials: P
authors.lastname: Schauerte
mesh_terms: D000375:Aging / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D001341:Autonomic Nervous System / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D015153:Blotting, Western; D002478:Cells, Cultured; D018507:Gene Expression Regulation, Developmental; D006321:Heart / Q000254:growth & development / Q000294:innervation*; D008297:Male; D020932:Nerve Growth Factor / Q000096:biosynthesis / Q000235:genetics*; D012313:RNA / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D012313:RNA; D020932:Nerve Growth Factor