Institute of Pharmcology Polish Academy of Sciences, Pharmacological Reports, 2(61), p. 325-329
DOI: 10.1016/s1734-1140(09)70039-8
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The inhibitory effect of agmatine on electrically induced contractions was studied in vas deferens of Adra 2a transgenic mice lacking alpha(2A)-adrenoceptors. Agmatine and clonidine caused a concentration-dependent inhibition of twitches. However, while agmatine showed a similar pIC(50) value in control and transgenic mice, the pIC(50) value for clonidine was about 30-fold lower in knockout mice. In both strains, yohimbine shifted the curve for clonidine, but not for agmatine, even when a 100-fold higher concentration of yohimbine was employed. Our results indicate that inhibition by agmatine in mouse vas deferens is not simply due to interactions with alpha(2)-adrenoceptors in our experimental conditions.