The opioid system has been implicated in major depression and in the mechanism of action of antidepressants. This study investigated the involvement of the opioid system in the antidepressant-like effect of the water-soluble B-vitamin folic acid in the forced swimming test (FST). The effect of folic acid (10 nmol/site, i.c.v.) was prevented by the pretreatment of mice with naloxone (1 mg/kg, i....

Opioid drugs such as heroin interact directly with opioid receptors whilst other addictive drugs, including marijuana, alcohol and nicotine indirectly activate endogenous opioid systems to contribute to their rewarding properties. The opioid system therefore plays a key role in addiction neurobiology and continues to be a primary focus for NIDA-supported research. Opioid receptors and their pep...

Chronic pruritus is frequently refractory to currently available treatments. Studies suggest that pruritus may arise from an imbalance of the mu- and kappa-opioid receptor system activity in either the skin or the central nervous system. Stimulation of kappa-opioid receptors by their agonists inhibits pruritus in both animals and humans. The antipruritic effect of kappa-opioid receptors agonist...

INTRODUCTION Opioids can produce potent analgesia by activating opioid receptors outside the central nervous system, thus avoiding centrally mediated unwanted effects. Peripheral opioid receptors are expressed in peripheral sensory (dorsal root ganglion) neurons and can interact with exogenous or endogenous opioid ligands both in animals and in humans. Inflammation of peripheral tissue leads to...

The gut is a neurological organ, which implies that many neuroactive drugs such as opioid analgesics can seriously disturb gastrointestinal function, because many of the transmitters and transmitter receptors present in the brain are also found in the enteric nervous system. One of the most common manifestations of opioid-induced bowel dysfunction is constipation which results from blockade of ...

Aims Our study sought to assess the prevalence of and risk factors for opioid drug dependence among out-patients on long-term opioid therapy in a large health-care system. Methods Using electronic health records, we identified out-patients receiving 4+ physician orders for opioid therapy in the past 12 months for non-cancer pain within a large US health-care system. We completed diagnostic inte...

27 * Department of Pharmacology, School of Pharmacy, Marmara University, T›bbiye Cad. No: 49 Haydarpafla, 81010 Istanbul, Turkey ° Corresponding author Opioid Control of Renal Excretion of Water and Sodium Summary : The kidneys act to regulate total body water and sodium via numerous neural and humoral mechanisms, including pathways that involve the renal sympathetic nerves, antidiuretic hormon...

Abstract Background Prediabetes is characterized by a hemoglobin A1c of 5.7–6.4% and fasting blood glucose 100–125 mg/dl. A high percentage prediabetes subjects develop type 2 diabetes mellitus in the next years. The effects opioid peptides their receptors, addition to immunological cytokines, on are not well understood. Therefore, molecular, physiological, clinical studies required link system...

Opioid receptors are widely expressed in the central and peripheral nervous system and in the non-neuronal tissues. Data from animal and human clinical studies support the involvement of peripheral opioid receptors in analgesia, especially in the presence of inflammation. Inflammation has been shown to increase the synthesis of opioid receptors in the dorsal root ganglion neurons and enhance tr...

Mitragynine, an indole alkaloid from Thai folk medicine Mitragyna speciosa, exerts agonistic effects on opioid receptors. Gastric acid secretion is proposed to be regulated by opioid receptors in the central nervous system (CNS). Previously, we reported the dual roles (inhibition via micro-opioid receptors and stimulation via kappa-opioid receptors) of the opioid system in the central control o...