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
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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
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