Delta opioid receptor

δ-Opioid receptors are a class of opioid receptor which have enkephalins as their endogenous ligands.

Function
Activation of the receptors produces analgesia. Some research suggests that they may also be related to seizures.

Until quite recently, there were few pharmacological tools for the study of δ receptors. As a consequence, our understanding of their function is much more limited than those of the other opioid receptors.

Recent work indicates that exogenous ligands which activate the delta receptors mimic the phenomenon known as ischemic preconditioning. Experimentally, if short periods of transient ischemia are induced the downstream tissues are robustly protected if longer-duration interruption of the blood supply is then effected.

Opiates and opioids with delta activity mimic this effect. In the rat model introduction of delta active ligands results in significant cardioprotection.