Dipropylacetate-induced shaking behaviour in the rat: a role of spinal α2-adrenoceptors

Abstract

The role of spinal adrenoceptors in di-n-propylacetate (DPA)-induced shaking behaviour was studied. The α 2-agonist p-aminoclonidine in a dose of 5 μg was found to suppress the DPA-induced body shakes when injected intrathecally but not when given intraventricularly. There was an enhancement of DPA-induced body shakes after the intrathecal injection of idazoxan while only a slight decrease was found after the intrathecal injection of prazosin. Intrathecal injection of idazoxan but not of prazosin proved to be effective to reverse the DPA-induced body shakes suppressed by p-aminoclonidine. Although the difference in effectiveness after intrathecal and intravenous injection was less than has been described for opiates there are several arguments that indicate an effect confined to the spinal cord. The present results further evidence the notion that the DPA-induced shaking behaviour shares common mechanisms with some of the morphine abstinence symptoms. The data indicate that spinal α 2-adrenoceptors are at least partly involved in the suppressive effect of p-aminoclonidine on DPA-induced shaking behaviour.