Type 1A dopamine receptor expression in the heart is not altered in spontaneously hypertensive rats

Citation
T. Matsumoto et al., Type 1A dopamine receptor expression in the heart is not altered in spontaneously hypertensive rats, AM J HYPERT, 13(6), 2000, pp. 673-677
Citations number
15
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cardiovascular & Respiratory Systems
Journal title
AMERICAN JOURNAL OF HYPERTENSION
ISSN journal
0895-7061 → ACNP
Volume
13
Issue
6
Year of publication
2000
Part
1
Pages
673 - 677
Database
ISI
SICI code
0895-7061(200006)13:6<673:T1DREI>2.0.ZU;2-H
Abstract
We have recently demonstrated that type 1A dopamine (D-1A) receptor is expr essed in the rat heart, but its function still remains unknown. In the pres ent study, we investigated possible changes in the expression level and the distribution of the cardiac D-1A receptor in the development of left ventr icular hypertrophy in spontaneously hypertensive rats/Izumo strain (SHR/Izm ) at the ages of 4, 8, and 20 weeks. We examined D-1A receptor protein dist ribution by immunohistochemistry and gene expression by competitive polymer ase chain reaction (competitive PCR). In SHR/Izm, compared with the age-mat ched Wistar Kyoto rats/ Izmo strain (WKY/Izm), blood pressure and heart/bod y weight ratio were significantly increased at 8 and 20 weeks. By immunohis tochemistry, the D-1A receptor was localized in cardiomyocytes and vascular smooth muscle cells of coronary arteries, but not in interstitial fibrotic tissue. D-1A receptor distribution was not changed either by the strain or the age. Competitive PCR analysis showed that the D-1A receptor mRNA level was significantly higher at 4 weeks than at 8 and 20 weeks in both strains of rats and that there was no significant difference in D-1A receptor mRNA between SHR/Izm and WKY/ Izm at any age (43.2 +/- 10.4 attomol x 10(-3)/L v 43.1 +/- 11.2 attomol x 10-3/L at 4 weeks, P = not significant, 3.9 +/- 0 .9 attomol x 10-3/L v 4.0 +/- 1.3 attomol x 10-3/L at 8 weeks, P = not sign ificant, 3.0 +/- 1.2 attomol x 10(-3)/L v 1.9 +/- 1.6 attomol x 10(-3)/L at 20 weeks, P = not significant). These results do not support the hypothesi s that changes in D-1A receptor expression are associated with the developm ent of left ventricular hypertrophy in SHR. Am J Hypertens 2000;13:673-677 (C) 2000 American Journal of Hypertension, Ltd.