Biologia, Bratislava, 55/Suppl. 8: 5-8, 2000.
ISSN 0006-3088 (Biologia). ISSN 1335-6399 (Biologia. Section Cellular and Molecular Biology).
Effect of long-term treatment with D-NAME and L-NAME with or without L-arginine on cardiovascular system in rats.
Pavel Babal1*, Ludovit Danihel1, Olga Pechanova2 & Iveta Bernatova2
1 Department of Pathology, Comenius University, Sasinkova 4, SK-81108 Bratislava, Slovakia; fax: ++ 421 7 5935 7592, e-mail: firstname.lastname@example.org
2 Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, Sienkiewiczova 1, SK-81371 Bratislava, Slovakia
* corresponding author
Received: July 10, 2000 / Accepted: October 24, 2000
Hemodynamic parameters, NO synthase activity and myocardial fibrosis were evaluated in male Wistar rats after one month treatment with 40 mg/kg/day of L-NAME, D-NAME, L-arginine 80 mg/kg/day and L-NAME plus 320 mg/kg/day of L-arginine. Myocardial NO synthase activity decreased by 42 and 25 % in the L- and D-NAME groups and by 41 % in the L-NAME with L-arginine group vs. control. The inhibition of NO synthase was accompanied by a significant elevation of systolic blood pressure in the D-NAME and L-NAME with or without L-arginine groups. There was no significant difference between the control and the L-arginine group. Myocardial fibrosis represented approx. 0.94 % in the control, 7.96 % in L-NAME, 5.25 % in D-NAME, 1.36 % in L-NAME with L-arginine and 1.05 % in the L-arginine group. The results indicate that D-NAME, although weaker then L-NAME, inhibits NO synthase activity resulting in hemodynamic and structural changes in the cardiovascular system. Although L-arginine prevented the development of myocardial fibrosis, it did not significantly decrease the NO synthase activity inhibition and systolic blood pressure.
Key words: nitric oxide synthase, L-NAME, D-NAME, L-arginine, hypertension, myocardial fibrosis, arterial hyperplasia.