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Cardiovascular System in Offsprings of
Hypertensive Rats with Defective Nitric Oxide Production
M. GEROVÁ, I. BERNÁTOVÁ, J.
TÖRÖK, M. JURÁNI1
Institute of Normal and Pathological
Physiology, Bratislava, and 1Institute of Animal
Biochemistry and Genetics, Ivanka pri Dunaji, Slovak Academy of
Sciences, Slovakia
Received October 10, 2001
Accepted January 22, 2002
Summary
The question was addressed of how nitric oxide synthase (NO
synthase) inhibition-induced hypertension in rat parents would
affect the cardiovascular system in their offsprings. Two
experimental groups were set up: Group I - offsprings of parents
who had both been administered NO synthase inhibitor
L-nitro-arginine methyl ester (L-NAME 40 mg/kg/day) for 5 weeks,
the treatment of dams continued till week 12. Group II -
offsprings fed by dams administered L-NAME after delivery only
for a period of 4 weeks. Control age-matched offsprings formed
the third group. Blood pressure and heart rate in parents and in
3-week-old offsprings were determined noninvasively. In the
offsprings, body and heart weight were measured and the
heart/body weight ratio (HW/BW) was calculated. The NO synthase
activity, and also ornithine decarboxylase activity as a marker
of polyamine production, were determined in the heart. The
acetylcholine-induced relaxation of aortic rings was also
followed. A marked blood pressure increase with a tendency to a
decreased heart rate was found in the offsprings of Group I. A
significant decrease in heart weight and body weight with a
decreased HW/BW ratio indicated cardiac hypotrophy that
contrasted with the decrease in NO synthase activity and
increase in ornithine decarboxylase activity in the heart.
Noteworthy was also the finding of completely preserved
relaxation of the aorta to acetylcholine. Offsprings of Group II
were similarly characterized by significantly higher blood
pressure, a tendency to decreased heart rate, a decrease in
heart weight, but not of the HW/BW ratio. The contrasting
findings of heart weight decrease on the one hand and NO
synthase activity decrease and ornithine decarboxylase increase
on the other, were also found in this group. Full relaxation of
the aorta to acetylcholine was preserved. It can be concluded
that remarkable alterations in the cardiovascular system were
found in offsprings of hypertensive NO compromised parents.
Key
words
Offsprings · Hypertension · Cardiac development · Nitric oxide ·
Ornithine decarboxylase
Reprint
requests
M. Gerová, MD DSc, Institute of Normal and Pathological
Physiology, Slovak Academy of Sciences, Sienkiewiczova 1, 813 71
Bratislava, Slovak Republic, Fax: +421-7-52968516. E-mail:
gerova@unpf.savba.sk
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