α 2-Adrenoceptor Antagonist SL84.0418 Involvement in the Development of Opioid Withdrawal

Title: α 2-Adrenoceptor Antagonist SL84.0418 Involvement in the Development of Opioid Withdrawal

Volume: 6 Issue: 2

Author(s): Anna Capasso and Chiara Gallo

Affiliation:

Keywords: antagonist, opioid receptor, guinea-pig, Morphine, pharmacological activity

Abstract: The effects exerted by a novel α2-adrenoceptor antagonist SL84.0418 on the acute opiate withdrawal induced by morphine (μ and κ opioid receptor agonist), DAMGO (highly selective μ opioid receptor agonist) and U-50488H (highly selective k opioid receptor agonist) was investigated in vitro. Furthermore, a comparative study was performed with yohimbine, a well known α2-adrenoceptor antagonist. Following a 4 min in vitro exposure to the opioid agonist, the guinea-pig isolated ileum exhibited a strong contracture after the addition of naloxone (80% of contraction vs acetylcholine control) whereas per se the addition of SL84.0418 and yohimbine before naloxone did not induce contracture. The addition of SL84.0418 (1x10-6-5x10-6-1x10-5 M) 10 min before each opioid agonist produced a concentrationdependent increase of the opioid withdrawal and its efficacy was comparable to yohimbine (1x10-6-5x10-6-1x10-5 M). The results of our experiments indicate that SL84.0418 is able to influence opiate withdrawal in vitro thus confirming an important functional interaction between the noradrenergic system and opioid withdrawal.

Cite this article as:

Capasso Anna and Gallo Chiara, α 2-Adrenoceptor Antagonist SL84.0418 Involvement in the Development of Opioid Withdrawal, Letters in Drug Design & Discovery 2009; 6 (2) . https://dx.doi.org/10.2174/157018009787582651