The opioid system is well conserved among species and plays a critical role in pain and addiction systems. The use of zebrafish as an experimental model to study development and genetics is extraordinary and has been proven to be relevant for the study of different diseases. The main drawback to its use for the analysis of different pathologies is the lack of protein tools. Antibodies that work...

The innate immune system modulates opioid-induced effects within the central nervous system and one target that has received considerable attention is the toll-like receptor 4 (TLR4). Here, we examined the contribution of TLR4 in the development of morphine tolerance, hyperalgesia, and physical dependence in two inbred mouse strains: C3H/HeJ mice which have a dominant negative point mutation in...

Pain is an unpleasant sensation that originates from ongoing or impending tissue damage. Management of different types of pain (acute, postoperative, inflammatory, neuropathic cancer) is challenging and yet the most frequent issue encountered by clinicians. Pharmacological therapy is the first line of approach for the treatment of pain and opioid drugs are prescribed for acute and chronic pain ...

OBJECTIVE To estimate the prevalence of constipation concomitant to opioid treatment and related resource use and costs from the private payer perspective. METHODS In this retrospective database analysis, patients receiving opioid therapy were identified from a longitudinal insurance claims database. An algorithm was used to identify patients receiving opioid therapy with coincident constipat...

Endogenous opioid peptides have been aligned with a diverse array of effects. Their activity is not only attributable to action the three main opioid receptors, mu (MOR), delta (DOR), and kappa (KOR) opioid receptors but their impacts appear to extend to activities at sodium channels, cytokine receptors (Finley et al., 2008), calcium channels and non-specific and partially undefined pharmacolog...

The opioids modulate reproduction in sheep mostly by inhibiting the activity of the hypothalamo-pituitary-gonadal axis. However, the mechanism by which the negative feedback control systems regulate opioid synthesis and secretion in sheep is still not recognized. As a part of a research dealing with interaction between opioids and steroids, the effect of prolonged administration of progesterone...

The discovery of the endogenous opioid peptide systems and their subsequent identification in human cerebrospinal fluid near 30 years ago triggered an intensive research to evaluate the function of these compounds in the clinical perspective. However, for this purpose it was necessary to develop reliable techniques with high sensitivity and reproducibility. Furthermore, it was necessary to asse...

CONTEXT There is extensive evidence implicating dysfunctions in stress responses and adaptation to stress in the pathophysiological mechanism of major depressive disorder (MDD) in humans. Endogenous opioid neurotransmission activating mu-opioid receptors is involved in stress and emotion regulatory processes and has been further implicated in MDD. OBJECTIVE To examine the involvement of mu-op...

Stimulation of the brain CCK2 receptor by the C-terminal octapeptide CCK8 of cholecystokinin (CCK) negatively modulates opioid responses. This suggests the existence of physiologically relevant interactions between endogenous CCK and opioid peptides, opening new perspectives particularly in the treatment of pain or drug addiction. CCK2 receptor-deficient mice were used to analyze the incidence ...

The opioid system (opioid peptides and receptors) regulates a variety of neurophysiologic functions, including pain control. Here we show novel roles of the κ opioid system in vascular development. Previously, we revealed that cAMP/protein kinase A (PKA) signaling enhanced differentiation of vascular progenitors expressing VEGF receptor-2 (fetal liver kinase 1; Flk1) into endothelial cells (ECs...