Effect of Captopril on Cyclic Nucleotide Concentrations
During Long-Term NO Synthase Inhibition
O. Pecháňová, I. Bernátová
Institute of Normal and Pathological Physiology, Slovak
Academy of Sciences, Bratislava, Slovak Republic
Received July
30, 1999
Accepted September 21, 1999
Summary
The aim of the present study was to determine the effect of
angiotensin-converting enzyme inhibitor captopril on cGMP and
cAMP concentration in the left ventricle and aorta after NO
synthase inhibition by 4-week-lasting NG-nitro-L-arginine-methyl
ester (L-NAME) treatment. Five groups of rats were investigated:
controls, L-NAME in the dose 20 mg/kg/day (L-NAME 20), L-NAME in
the dose 40 mg/kg/day (L-NAME 40), captopril in the dose 100
mg/kg/day, L-NAME 40 mg/kg/day together with captopril 100
mg/kg/day. Captopril completely prevented L-NAME-induced
hypertension and LV hypertrophy development. Compared to the
controls, cGMP concentration in the L-NAME 20 and L-NAME 40
groups was decreased by 13 % and 22 %, respectively, in the left
ventricle and by 27 % and 56 % in the aorta, respectively.
Captopril did not influence this decrease of cGMP concentration.
Cyclic AMP concentration in the aorta of L-NAME 20 group
increased by 17 %. In the L-NAME 40 group, cAMP concentration
increased by 17 % in the left ventricle and by 34 % in the aorta
compared to controls. This increase was enhanced in rats given
L-NAME together with captopril. Captopril alone had no effect on
cAMP concentration. We conclude that captopril does not affect
the concentration of cGMP, however, it has more than the
additive effect on the cAMP concentration increase in the
cardiovascular system during long-term NO synthase inhibition.
Key
words
Nitric oxide · NO synthase · Cyclic nucleotides · L-NAME · ACE inhibitor ·
Hypertension
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O. Pecháňová, Institute of Normal and Pathological Physiology, Slovak Academy of
Sciences, Sienkiewiczova 1, 813 71 Bratislava, Slovak Republic. E-mail: pechan@unpf.savba.sk
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