title: The influence of age on serum concentrations of cardiac troponin I: results in rats, monkeys, and commercial sera.
abstract: Cardiac troponins serve as serum biomarkers of myocardial injury. The current study examined the influence of age on serum concentrations of cardiac troponin I (cTnI). An ultrasensitive immunoassay was used to monitor cTnI concentrations in Sprague-Dawley (SD) rats and Erythrocebus patas monkeys of different ages. The mean cTnI concentrations were highest in 10-day-old rats compared to 25-, 40-, and 80-day-old SD rats. Cardiomyocyte remodeling was apparent in hearts from 10-day-old SD rats as evident by hypercellularity, irregularly shaped nuclei, and moderate numbers of myocytes undergoing mitosis and apoptosis. The mean concentration of cTnI in 5 newborn monkeys was considerably higher than that of three 1-year-old monkeys. Evidence of cardiomyocyte remodeling was also observed in these newborn hearts (loss of myofibrils and cytoplasmic vacuolation). Commercial animal serum samples were also analyzed. The concentrations of cTnI detected in fetal equine and porcine serum were considerably higher than that found in adult equine and porcine serum samples Likewise, fetal bovine serum had higher cTnI concentrations (>2,400 pg/ml) than did adult caprine and laprine samples (2.5-2.7 pg/ml). The present study found age-related differences in cTnI concentrations, with higher levels occurring at younger ages. This effect was consistent across several animal species.
authors.affiliation: Food and Drug Administration, Division of Drug Safety Research, Silver Spring, Maryland, USA eugene.herman@fda.hhs.gov.
authors.forename: Eugene H
authors.initials: EH
authors.lastname: Herman
authors.affiliation: Food and Drug Administration, Division of Drug Safety Research, Silver Spring, Maryland, USA.
authors.forename: Alan
authors.initials: A
authors.lastname: Knapton
authors.affiliation: National Institutes of Health, National Cancer Institute, Carcinogen-DNA Interactions Section, Bethesda, Maryland, USA.
authors.forename: Yongmin
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Pediatrics, Leonard M. Miller School of Medicine, Mailman Center for Child Development, University of Miami, Miami, Florida, USA.
authors.forename: Steven E
authors.initials: SE
authors.lastname: Lipshultz
authors.affiliation: Singulex, Inc., Alameda, California, USA.
authors.forename: Joel
authors.initials: J
authors.lastname: Estis
authors.affiliation: Singulex, Inc., Alameda, California, USA.
authors.forename: John
authors.initials: J
authors.lastname: Todd
authors.affiliation: Shared Animal Facility, NIH Animal Center, Dickerson, Maryland, USA.
authors.forename: Ruth A
authors.initials: RA
authors.lastname: Woodward
authors.affiliation: Department of Pediatrics, Leonard M. Miller School of Medicine, Mailman Center for Child Development, University of Miami, Miami, Florida, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Cochran
authors.affiliation: Food and Drug Administration, Division of Drug Safety Research, Silver Spring, Maryland, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: National Institutes of Health, National Cancer Institute, Carcinogen-DNA Interactions Section, Bethesda, Maryland, USA.
authors.forename: Miriam C
authors.initials: MC
authors.lastname: Poirier
mesh_terms: D000367:Age Factors; D000818:Animals; D015415:Biomarkers / Q000097:blood*; D002417:Cattle; D004901:Erythrocebus patas; D005260:Female; D006335:Heart Injuries / Q000097:blood; D006736:Horses; D007118:Immunoassay; D008297:Male; D009206:Myocardium / Q000378:metabolism; D009210:Myofibrils / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013552:Swine; D019210:Troponin I / Q000097:blood*
chemical_list: D015415:Biomarkers; D019210:Troponin I
keywords:  patas monkeys; Sprague-Dawley rats; cardiac troponin I; young age.