Cardiac troponin I in isoproterenol-induced cardiac injury in the Hanover Wistar rat: studies on low dose levels and routes of administration.
The current studies demonstrate the effect of low-dose intraperitoneal (IP) administration of isoprotenerol (ISO) and subcutaneous (SC) versus IP routes of administration of ISO on serum cardiac troponin I (cTnI) levels in female Hanover Wistar rats, providing additional evidence to support acceptance of cTnI as a cardiac biomarker. At 2 hr postdosing with 0-500 microg/kg ISO, mean serum cTnI levels were increased in a dose-related fashion at > or =10 microg/kg with no evidence of cardiac pathology. At 24 h, cTnI concentrations were generally at control levels, but histologic cardiomyocyte injury was evident in a proportion of the animals given > or =10 microg/kg. In a second experiment, rats given SC ISO at 5,000 microg/kg and necropsied at 0, 1, 2, and 4 hr postdosing had higher levels of serum cTnI than animals given the same dose IP.
Brady
Sally
S
Centre for Toxicology, Department of Pharmacology, School of Pharmacy, University of London.
York
Malcolm
M
Scudamore
Cheryl
C
Williams
Thomas
T
Griffiths
William
W
Turton
John
J
D000818:Animals; D015415:Biomarkers / Q000097:blood; D004305:Dose-Response Relationship, Drug; D005260:Female; D006335:Heart Injuries / Q000097:blood* / Q000139:chemically induced / Q000473:pathology; D007274:Injections, Intraperitoneal; D007279:Injections, Subcutaneous; D007545:Isoproterenol / Q000008:administration & dosage / Q000633:toxicity*; D009206:Myocardium / Q000473:pathology; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D019210:Troponin I / Q000097:blood*
D015415:Biomarkers; D019210:Troponin I; D007545:Isoproterenol