Opiod receptor

The nociceptin/orphanin FQ (N/OFQ)-Nociceptin Opiod-like Peptide (NOP) receptor system is a critical mediator of physiological and pathological processes involved in emotional regulation and drug addiction. As such, this system may be an important biological substrate underlying psychiatric conditions that contribute to the risk of suicide. Thus, the goal of the present study was to characterize changes in human N/OFQ and NOP signaling as a function of depression, addiction and suicide. We quantified the expression of N/OFQ and NOP by RT-PCR in the anterior insula, the mediodorsal thalamus, and the dorsal anterior cingulate cortex (dACC) from a large sample of individuals who died by suicide and matched psychiatrically-healthy controls...

The most well-known physiological effect associated with opiod system is their efficacy in pain reduction or analgesia, although their effect on a variety of other physiological and physiophological functions has become apparent in recent years. This review is an attempt to clarify in more detail the epigenetic regulation of opioid system to understand with more precision their transcriptional and posttranscriptional regulation in multiple pyisiological and pharmacological contexts. The opioid receptors show an epigenetic regulation and opioid peptide precursors by methylation, chromatin remodeling and microRNA...

Seed oil (Pp-oil) of Plukenetia polyadenia is used by native people of the Brazilian Amazon against arthritis and rheumatism, spreading it on the arms and legs to reduce the pain and inflammation. Pp-oil was obtained by pressing dried seeds at room temperature to give a 47.0% yield of oil. It was then subjected to fatty acid composition analysis. The principal fatty acids were linoleic acid (46.5%), α-linolenic acid (34.4%) and oleic acid (13.9%). Then, it was evaluated for its antinociceptive activity in mice, using the acetic acid-induced abdominal writhing, hot plate and formalin test models...

The adrenal medulla plays a key role in the physiological responses of developing and mature mammals by releasing catecholamines (CAT) during stress. In rodents and humans, the innervation of CAT-producing, adrenomedullary chromaffin cells (AMCs) is immature or absent during early postnatal life, when these cells possess 'direct' hypoxia- and CO2/H(+)-chemosensing mechanisms. During asphyxial stressors at birth, these mechanisms contribute to a CAT surge that is critical for adaptation to extra-uterine life...

In humans, hibernoma is a very rare, benign neoplasm of brown adipose tissue (BAT) that typically occurs at subcutaneous locations and is successfully treated by surgical excision. No single cause has been accepted to explain these very rare human tumors. In contrast, spontaneous hibernoma in rats is rare, often malignant, usually occurs in the thoracic or abdominal cavity, and metastases are common. In recent years, there has been an increased incidence of spontaneous hibernomas in rat carcinogenicity studies, but overall the occurrence remains relatively low and highly variable across studies...

With the prevalence of diabetes mellitus (DM) increasing, pathologic complications such as diabetic peripheral neuropathy (DPN) are also becoming more common. Of those diagnosed with DM, 10% to 20% of patients suffer from painful DPN. Until recently, only pregabalin and duloxetine possessed Food and Drug Administration (FDA) approval for this condition. However, FDA recently approved tapentadol-ER [extended release] (Nucynta ER) for painful DPN. Tapentadol-ER is an opioid analgesic commonly used for the treatment of moderate-to-severe chronic pain that contains a unique dual mechanism acting as both a weak mu-opiod receptor agonist and norepinephine-reuptake inhibitor...

BACKGROUND: The peripheral nerve endings carrying pain contains opiod receptors. Blocking these receptors during haematoma block or periosteal block may provide better analgesia. AIM: Evaluation of effectiveness and safety of butorphanol as an adjuvant to lidocaine for haematoma block. SETTINGS AND DESIGN: This is a two centre, prospective, individually randomised, two group, parallel, double-blind clinical trial. METHODS: In this study, 115 American society of anaesthesiologist grade I and II adult patients scheduled for closed reduction of fractures were randomly allocated into two groups; Group A received 1% lidocaine (2 mg/kg) where as Group B received 1% lidocaine (2 mg/kg) with butorphanol (0...

BACKGROUND: Opioids may cause progressive enhancement of pain sensitivity (opioid-induced hyperalgesia [OIH]) and thus, exacerbate existing pain. Animal studies also demonstrate paradoxical OIH with an ultralow dose (ULD, subanalgesic) of opioid; eg, the μ-opioid, morphine. Repeated administration of ULD-morphine resulted in tolerance to ULD-OIH. Prior exposure to ULD-morphine prolonged subsequent morphine antinociception in intact rats (delay of tolerance) and blocked neuropathic pain in nerve-injured rats (no hyperalgesia)...

Social bonds are important for human health and well-being, and a crucial component of these bonds is the ability to maintain a bond once it has been formed. Importantly, although bond maintenance is required for social attachments, very little is known about the neural mechanisms that mediate this behavior. Recently, laboratory studies utilizing the socially monogamous prairie vole (an excellent animal model for the neurobiology of selective social attachment), have allowed the neural correlates of selective social attachment to begin to unfold...

Various new agents are in the research pipeline for atopic dermatitis. These include IL-4 receptor antagonist, cis-urocanic acid, κ-opiod receptor agonist, neurokinin receptor antagonist and antimicrobial peptide. The current review updates the status of these clinical trials and provides insight into other potential molecular targets including IL-22 and TLR-2.

OBJECTIVE: To investigate the efficacy, safety and tolerability of topical nalmefene (SRD174), a long acting opioid antagonist for the management of pruritus associated with atopic dermatitis (AD). DESIGN: Double-blind, vehicle-controlled, randomized, cross-over trial. SETTING: Eleven dermatology outpatient clinics in the U.S. PATIENTS: Sixty-two out of 136 screened adult subjects with confirmed AD affecting is less than or equal to 20% of body surface area and with moderate-to-severe pruritus...

Docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid (n-3 PUFAs), is an essential polyunsaturated fatty acid in the central nervous system, and possesses many physiological functions in neurodegenerative diseases. Previously, there are some reports that n-3 PUFAs contribute to pain relief. As the antinociceptive effect of DHA alone has not been reported, this study examined the antinociceptive effect of DHA on various pain stimuli. To evaluate the antinociceptive effect of DHA on thermal and chemical nociception, we employed the tail flick test, acetic acid writhing test and formalin test in mice...

Previous reports suggest that melatonin may play an important role in visceral nociception and neurogenic inflammation. We aimed to examine the role of melatonin on visceral hypersensitivity and to explore the site of action using a rat model of post-inflammatory visceral hyperalgesia. In all rats, a baseline viscero-motor response (VMR) to graded colorectal distension (CRD; 10-60mmHg) was recorded prior and 1 week following tri-nitrobenzenesulfonic acid (TNBS) induced colonic inflammation. Melatonin (30, 45 or 60mg/kg, ip) was given 20min before testing the VMR in naïve and TNBS-treated rats...

Salvia divinorum is widely cultivated in the US, Mexico, Central and South America and Europe and is consumed for its ability to produce hallucinogenic effects similar to those of other scheduled hallucinogenic drugs, such as LSD. Salvinorin A (SA), a kappa opiod receptor agonist and psychoactive constituent, is found primarily in the leaves and to a lesser extent in the stems of the plant. Herein, the analysis of intact S. divinorum leaves for SA and of acetone extracts separated using thin layer chromatography (TLC) is demonstrated using desorption electrospray ionization (DESI) mass spectrometry...

Chronic kidney disease (CKD)-associated pruritus is a significant clinical symptom affecting more than 50% of patients on hemodialysis. Restricted by the availability of effective therapeutic options, the management of CKD-associated pruritus remains a treatment challenge. Evaluating research in this area is difficult, as most studies are not comparable due to differing methodologies and study designs, limited number of patients, and the lack of standardized measures. The most frequently used therapy is UVB phototherapy, eliciting favorable responses in most patients...

Several drugs acting on the nervous system have been implicated in the prolongation of the QT interval. Leaving aside the antidepressant and antipsychotic drugs, some have shown to prolong the QT interval in vivo. These include opioids, particularly methadone, inhalational anesthetics, and some preparations used for treatment of cough. These drugs have a narrow therapeutic interval or possible drug interactions that lead to clinical toxicity manifested by arrhythmias. They share the ability to block potassium channels (HERG), prolong the action potential and QT interval, and generate arrhythmias and Torsades de Pointes like other typicality recognized like antiarrhythmics, antihistamines, prokinetics, psychotropics and anti-infectives agents...

BACKGROUND: There is evidence from animal studies that serotonin (5-HT) can influence the antinociceptive effects of opioids at the spinal cord level. Therefore, there could be an influence of genetic polymorphisms in the serotonin system on individual variability in response to opioid treatment of pain. The serotonin transporter (5-HTT) is a key regulator of serotonin metabolism and availability and its gene harbors several known polymorphisms that are known to affect 5-HTT expression (e...

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease, affecting 10-20% of children and 2% of adults worldwide. Preventive treatment of AD consists of daily skin hydration and emollient therapy; but the majority of patients still require symptomatic treatment with topical corticosteroids and/or topical calcineurin inhibitors, both of which may be associated with potential long-term side effects. With increasing evidence supporting the role of skin barrier defects in the pathogenesis of AD, there is also a parallel increase in medications that claim to assist barrier repair...

Recently, we have demonstrated that substitution of 1,2,3,4 tetrahyidroisoquinoline-3- carboxylic acid (Tic) in place of Gly2 in dynorphin A-(1-13)-NH2 (DYN) analogue (A) decreased the affinity to the kappa, delta, and micro receptors, and kappa selectivity. The doubly substituted analogue [2',6'-dimethyl-L-tyrosine (Dmt1)-Tic2]DYN (B) exhibited high delta-affinity (Ki=0.39 nM) while micro- and kappa-affinities were only an order of magnitude less (4-5 nM). Bioactivity of [Tic2]DYN peptide (A) on guinea-pig ileum and rabbit jejunum revealed potent delta- and kappa-antagonism thus indicating that the conversion from a kappa-agonist to antagonist occurred with the inclusion of Tic into DYN analogues, similar to the appearance of antagonist properties with delta-opioid agonists containing a Tic2 residue...

A sixth month phase II multicenter-pilot trial with a low dose of the opiate antagonist Naltrexone (LDN) has been carried out in 40 patients with primary progressive multiple sclerosis (PPMS). The primary end points were safety and tolerability. Secondary outcomes were efficacy on spasticity, pain, fatigue, depression, and quality of life. Clinical and biochemical evaluations were serially performed. Protein concentration of beta-endorphins (BE) and mRNA levels and allelic variants of the mu-opiod receptor gene (OPRM1) were analyzed...