Differences in time course of myocardial mRNA expression in non-infarcted myocardium after myocardial infarction |
| |
Authors: | Takashi Omura Minoru Yoshiyama Kazuhide Takeuchi Akihisa Hanatani Shokei Kim Ken Yoshida Yasukatsu Izumi Hiroshi Iwao Junichi Yoshikawa |
| |
Institution: | (1) First Department of Internal Medicine, Osaka City University Medical School, 1-5-7 Asahimachi, Abneno-ku, Osaka 545, Japan, JP;(2) Department of Pharmacology, Osaka City University Medical School, Osaka 545-8586, Japan, JP |
| |
Abstract: | In non-infarcted myocardium after myocardial infarction, the change of cardiac phenotypic modulation of contractile protein,
extracellular matrix and intracellular Ca2+ transport protein, such as sarcoplasmic reticulum Ca2+(SR-Ca2+)-ATPase, Na+-Ca2+ exchanger, have a important role during cardiac remodeling. However, the time course in this gene expression in the adjacent
and remote left ventricular, or right ventricular myocardium after myocardial infarction has not been well examined. The purpose
of this study was to examine the left ventricular function and regional cardiac gene expression after myocardial infarction.
Myocardial infarction was produced in Wistar rats by the ligation of the left anterior descending coronary artery. After 3
weeks, 2 months and 4 months from myocardial infarction, we performed Doppler echocardiography and measured the systolic and
diastolic function. Then, we analyzed the contractile protein, extracellular matrix and intracellular Ca 2+ transport protein mRNAs of cardiac tissues in the adjacent and the remote noninfarcted myocardium, and right ventricular
myocardium by Northern blot hybridization. Fractional shortening of infarcted heart progressively decreased. Peak early diastolic
filling wave (E wave) velocity increased, and the deceleration rate of the E wave velocity was more rapid in myocardial infarction
areas. Atrial filling wave (A wave) velocity decreased, resulting in a marked increase in the ration of E wave to A wave velocity.
Expression of myocardial α-skeletal actin, β-MHC and ANP mRNA, or collagen I and III mRNA were higher at 3 weeks after myocardial
infarction. SR Ca2+-ATPase mRNA in the adjacent non-infarcted myocardium was decreased at 2 months, and that in remote myocardium was decreased
at 4 months after infarction. Na+-Ca2+ exchanger mRNA levels were increased at 3 weeks, but was decreased at 2 months in the adjacent non-infarcted myocardium and
at 4 months in the remote myocardium. These findings suggest that the compensation for myocardial infarction by myocardial
gene expression in non-infarcted myocardium may occur at an early phase after myocardial infarction, and myocardial dysfunction
may begin from adjacent to remote non-infarcted myocardium during progressive cardiac remodeling.
Received: 9 August 1999, Returned for revision: 16 September 1999, Revision received: 5 January 2000, Accepted: 26 January
2000 |
| |
Keywords: | Cardiac remodeling – Doppler echocardiography – myocardial infarction – mRNA – Sarcoplasmic reticulum Ca2+-ATPase – Na+-Ca2+ exchanger |
本文献已被 PubMed SpringerLink 等数据库收录! |
|