126876-64-0Relevant articles and documents
δ Opioid Antagonist Activity and Binding Studies of Regioisomeric Isothiocyanate Derivatives of Naltrindole: Evidence for δ Receptor Subtypes
Portoghese, P. S.,Sultana, M.,Nelson, W. L.,Klein, P.,Takemori, A. E.
, p. 4086 - 4091 (2007/10/02)
The isothiocyanate group was attached to the 4'-, 5'-, 6'-, or 7'-position of naltrindole in an effort to determine the importance of the position of this electrophilic group on the selectivity for subtypes of δ opioid receptors. All of the ligands were δ-selective when tested against standard agonists in smooth muscle preparations. However, the rank-order δ antagonism of antinociception in mice did not parallel the in vitro pharmacologic data. The 5'-isothiocyanate 2 was the most potent and selective antagonist in vivo, causing a 52-fold increase of the ED50 for2,D-Leu5>enkephalin-Thr6 (DSLET) and no increase for 2,D-Pen5>enkephalin (DPDPE). The effect of each of the ligands on the binding of 3H>DSLET and 3H>DPDPE to guinea pig brain membranes clearly differentiated between the binding sites that recognize these radioligands. These studies provide additional evidence for the presence of two subtypes of δ opioid receptors.
