Haemodynamic changes and acetylcholine-induced hypotensive responses after NG-nitro-L-arginine methyl ester in rats and cats. |
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| Authors: | E. Marcel van Gelderen J. P. Heiligers P. R. Saxena |
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| Affiliation: | Department of Pharmacology, Faculty of Medicine and Health Sciences, Erasmus University Rotterdam, The Netherlands. |
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| Abstract: | 1. The haemodynamic effects of NG-nitro-L-arginine methylester (L-NAME; 1, 3, 10 and 30 mg kg-1) and its potential ability to attenuate the hypotensive responses to acetylcholine (0.03, 0.1, 1.0 and 3.0 micrograms kg-1) have been investigated in anaesthetized rats and cats. 2. In the rat, L-NAME elicited a dose-dependent pressor effect increasing mean arterial blood pressure from the baseline value of 116 +/- 4 mmHg to a maximum of 156 +/- 6 mmHg with 30 mg kg-1. This increase in blood pressure could be only partly reversed by L-arginine (300 mg kg-1). However, the increase in blood pressure by lower doses (up to 10 mg kg-1) of L-NAME was effectively reversed by L-arginine (1000 mg kg-1). 3. In the cat, L-NAME did not significantly modify systemic haemodynamic variables (heart rate, mean arterial blood pressure, cardiac output, stroke volume or total peripheral resistance), when compared to the changes in saline-treated animals. Administration of L-arginine did not cause any significant effect in cats treated with L-NAME, but some decrease in heart rate and increases in cardiac output and stroke volume were observed in the saline-treated group. 4. With the lowest dose (1 mg kg-1), L-NAME did not affect tissue blood flows in the cat, but higher doses (3 and 30 mg kg-1) significantly reduced blood flows to the mesentery, stomach, spleen, intestines, lungs and the total liver.(ABSTRACT TRUNCATED AT 250 WORDS) |
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