Time-related adaptations in plasma neurohormone levels and hemodynamics after myocardial infarction in the rat.
BACKGROUND
Neurohormonal activation plays an important role in the progression of heart failure. In this study, we investigated the progression of neurohormonal activation in conjunction with the hemodynamic status of the rat after myocardial infarction (MI).


RESULTS
Male Wistar rats were subjected to sham or MI surgery. At 1, 3, 5, and 13 weeks after surgery, cardiac output (CO), mean arterial pressure (MAP), and total peripheral resistance (TPR), were measured. In separate groups of rats, blood was sampled at 1, 5, and 13 weeks after surgery and analyzed for various neurohormones. At 1 week after surgery, CO and TPR were not altered in MI rats, but plasma neurohormonal levels were elevated. At 3 and 5 weeks after surgery, reduced CO, increased TPR, and normal MAP were measured in MI rats compared to sham rats, but only endothelin levels were elevated. At 13 weeks after surgery, MAP was reduced in MI rats and CO and TPR were comparable between groups. Neurohormonal activation was again apparent in MI rats.


CONCLUSIONS
Myocardial infarction in the rat induces early neurohormonal activation, which normalizes hemodynamic parameters. A compensatory phase follows. At 13 weeks after MI, plasma concentrations of neurohormones are again elevated, perhaps as a sign of transition to decompensation.
Ceiler
D L
DL
Department of Pharmacology, Cardiovascular Research Institute Maastricht, Universiteit Maastricht, The Netherlands.
Schiffers
P M
PM
Nelissen-Vrancken
H J
HJ
Smits
J F
JF
D000222:Adaptation, Physiological; D000818:Animals; D018450:Disease Progression; D006439:Hemodynamics; D008297:Male; D009203:Myocardial Infarction / Q000097:blood* / Q000503:physiopathology*; D018377:Neurotransmitter Agents / Q000097:blood*; D051381:Rats; D017208:Rats, Wistar; D018487:Ventricular Dysfunction, Left / Q000097:blood
D018377:Neurotransmitter Agents