# name
Remote local photoactivation of morphine produces analgesia without opioid-related adverse effects

# metadata.dc.description.abstract[].value
Background and purpose: Opioid-based drugs are the gold standard medicines for pain relief. However, tolerance and several side effects (i.e. constipation and dependence) may occur upon chronic opioid administration. Photopharmacology is a promising approach to improve the benefit/risk profiles of these drugs. Thus, opioids can be locally activated with high spatiotemporal resolution, potentially minimizing systemic-mediated adverse effects. Here, we aimed at developing a morphine photo-derivative (photocaged morphine), which can be activated upon light irradiation both in vitro and in vivo.

Experimental approach: Light-dependent activity of pc-morphine was assessed in cell-based assays (intracellular calcium accumulation and electrophysiology) and in mice (formalin animal model of pain). In addition, tolerance, constipation and dependence were investigated in vivo using experimental paradigms.

Key results: In mice, pc-morphine was able to elicit antinociceptive effects, both using external light-irradiation (hind paw) and spinal cord implanted fibre-optics. In addition, remote morphine photoactivation was devoid of common systemic opioid-related undesired effects, namely, constipation, tolerance to the analgesic effects, 
rewarding effects and naloxone-induced withdrawal.

Conclusion and implications: Light-dependent opioid-based drugs may allow effective analgesia without the occurrence of tolerance or the associated and severe opioid-related undesired effects.

# metadata.dc.relation.ispartof[].value
British Journal of Pharmacology, 2021, vol. 180, num.7, p. 958-974

# metadata.dc.rights[].value
cc-by-nc (c) López-Cano, Marc et al., 2021

# metadata.dc.source[].value
Articles publicats en revistes (Patologia i Terapèutica Experimental)

# metadata.dc.title[].value
Remote local photoactivation of morphine produces analgesia without opioid-related adverse effects