Volume 50: 35-42, 2001

 

Different Expression of Renin-Angiotensin System Components in Hearts of Normotensive and Hypertensive Rats

D. JURKOVIČOVÁ, Z. DOBEŠOVÁ1, J. KUNEŠ1, O. KRIŽANOVÁ

Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava, Slovak Republic and 1Institute of Physiology, Czech Academy of Sciences of the Czech Republic, Prague, Czech Republic

Received February 2, 2000
Accepted July 12, 2000

Summary
Tissue renin-angiotensin systems are known to behave differently from the circulating renin-angiotensin system (RAS). It has already been proposed that not only the circulating RAS, but also RAS localized in the cardiac tissue plays an important role in the heart failure. The objective of this study was to compare the gene expression of individual components of the renin-angiotensin system in hearts of normotensive and hypertensive rats. Two genetically hypertensive rat strains - spontaneously hypertensive rats (SHR) and hereditary hypertriglyceridemic rats (HTG) - were compared with Wistar-Kyoto (WKY) and Lewis (LEW) normotensive controls. In addition, developmental changes in gene expression of individual components of cardiac RAS were studied in 20-day-old fetuses, 2-day-old newborns and 3-month-old HTG and LEW rats. In our study, the angiotensinogen gene expression did not differ either among adult normotensive and hypertensive strains, or during development. In contrast, the renin gene expression was significantly increased in hearts of hypertensive compared to normotensive rats. Moreover, a 5-fold increase of renin mRNA was observed in hearts of HTG rats between day 2 and the third month of age. There was also an age-dependent increase of ACE gene expression in both HTG and LEW rats which was substantially delayed in HTG hearts. In conclusion, the results of our study suggest that overexpression of the cardiac renin gene in hypertensive strains could participate in the structural and functional changes of the heart during the development of hypertension.


Key words
Renin-angiotensin system · Development · Heart · Gene expression · Hypertension

Reprint requests
Dr. Oľga Križanová, Ph.D., Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Vlárska 5, 833 34 Bratislava, Slovak Republic, e-mail: umfgkriz@kramare.savba.sk

 

PHYSIOLOGICAL RESEARCH
© 2001 by the Institute of Physiology, Czech Academy of Sciences

ISSN 0862 - 8408

Issue 1