naloxone and Melanoma

In this large population-based cohort, individuals with more-severe obesity, central obesity, or genetic predisposition for obesity are at higher risk of developing severe-COVID-19.. The use of different references for the classification of a high %BF implied a difference in the diagnostic sensitivity of the BMI. Higher cutoff points resulted in greater sensitivity and ability to differentiate individuals with and without obesity.

Topics: Acyclic Monoterpenes; Adipose Tissue; Adolescent; Adult; Aged; Aged, 80 and over; Air Pollutants; Air Pollutants, Occupational; Amino Acid Transport Systems; Analgesics, Opioid; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Arthrobacter; Bacteria; Bacteriological Techniques; Benzaldehydes; Biodegradation, Environmental; Biofilms; Biological Transport; Biomarkers; Biomass; Bioreactors; Body Composition; Body Mass Index; Brassica; Brazil; Buprenorphine; Buprenorphine, Naloxone Drug Combination; Caco-2 Cells; Cadmium; Calcium; Calcium Carbonate; Calcium Channels; Catalysis; Cell Degranulation; Cell Line; Cell Membrane; Chitosan; Chromatography, High Pressure Liquid; Chromium; Cobalt; Cohort Studies; Colony Count, Microbial; Composting; Copper; COVID-19; Cross-Sectional Studies; Cytoplasm; Delayed-Action Preparations; Diabetes Mellitus, Type 2; Diarrhea; Diethylhexyl Phthalate; Dose-Response Relationship, Drug; Drug Implants; Drug Stability; Drug Synergism; Electroplating; Endometrial Neoplasms; Endometrium; Environmental Monitoring; Environmental Restoration and Remediation; Estradiol; Estrogens; Feces; Female; Food Microbiology; Food Preservation; Fruit and Vegetable Juices; Gasotransmitters; Gastrointestinal Diseases; Gastrointestinal Microbiome; Gene Expression Regulation, Developmental; Genetic Predisposition to Disease; Glutathione; Gold; Graphite; Growth Hormone; Harm Reduction; Hot Temperature; Humans; Hydrocortisone; Hydrogen; Hydrogen Peroxide; Hydrogen Sulfide; Hydrogen-Ion Concentration; Ileum; Imidazoles; Injections, Intraperitoneal; Insecticides; Insulin-Like Growth Factor Binding Protein 1; Insulin-Like Growth Factor Binding Protein 2; Insulin-Like Growth Factor Binding Protein 5; Insulin-Like Growth Factor I; Intestinal Absorption; Light; Lignin; Liver; Magnetics; Male; Manganese; Mast Cells; Melanoma; Membrane Potentials; Metals; Methadone; Microbial Viability; Microplastics; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Middle Aged; Mitochondrial Swelling; Molecular Dynamics Simulation; Monophenol Monooxygenase; Morocco; Naloxone; Naltrexone; Nanocomposites; Nanomedicine; Nanoparticles; Narcotic Antagonists; Neonicotinoids; Nitric Oxide; Nitro Compounds; Nitrogen; Nitrogen Compounds; Obesity; Obesity, Abdominal; Occupational Exposure; Ontario; Opiate Substitution Treatment; Opioid-Related Disorders; Oryza; Overweight; Oxidative Stress; Oxides; Oxygen; Perception; Photoelectron Spectroscopy; Plants; Plastics; Point Mutation; Polychlorinated Biphenyls; Polycyclic Aromatic Hydrocarbons; Potassium; Premenopause; Prodrugs; Prospective Studies; Protons; Pyrolysis; Qualitative Research; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Resins, Synthetic; Rhodamines; Risk Factors; ROC Curve; Salmo salar; SARS-CoV-2; Seawater; Severity of Illness Index; Sewage; Social Media; Soil; Soil Microbiology; Soil Pollutants; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis, Raman; Staining and Labeling; Stainless Steel; Steel; Stress, Physiological; Substance Abuse Treatment Centers; Symporters; T-Lymphocytes; Toluene; Triclosan; Ultraviolet Rays; Waist Circumference; Waste Disposal, Fluid; Wastewater; Water Purification; Welding; X-Ray Diffraction; Young Adult

Fentanyl is an opioid commonly prescribed for cancer pain. Using melanoma-bearing mice, we investigated whether peripheral action would contribute to fentanyl analgesia in cancer pain. Intravenous injection of fentanyl inhibited mechanical nociception in healthy mice, which was markedly inhibited by the opioid antagonist naloxone, but not naloxone methiodide, a peripherally acting opioid antagonist. Melanoma-bearing mice showed mechanical allodynia and spontaneous licking, a pain-related behavior, which were suppressed by intravenous and local injections of fentanyl. Both naloxone and naloxone methiodide inhibited the analgesic effect of intravenous fentanyl to the same degree. Electrophysiological analysis showed that melanoma growth increased the spontaneous and mechanical stimuli-evoked activity of the tibial nerve, which were inhibited by intravenous fentanyl. There was a greater expression of µ- opioid receptors in skin with a melanoma mass than in the contralateral normal skin. In addition, we found µ-opioid receptors in cultured melanoma cells. There was no difference between the number of µ-opioid receptors in the dorsal root ganglia and spinal cord of the melanoma-bearing and contralateral skin side. These results suggest that the analgesic effect of systemic fentanyl is produced via central and peripheral µ- opioid receptors in cancer pain, and cancer cells are a key site of peripheral action.

Topics: Action Potentials; Analgesics, Opioid; Animals; Cancer Pain; Cell Line, Tumor; Disease Models, Animal; Fentanyl; Humans; Hyperalgesia; Injections, Intramuscular; Injections, Intravenous; Male; Melanoma; Mice; Mice, Inbred C57BL; Naloxone; Narcotic Antagonists; Quaternary Ammonium Compounds; Receptors, Opioid; Receptors, Opioid, mu; Skin; Skin Neoplasms; Spinal Cord; Tibial Nerve; Xenograft Model Antitumor Assays

The present study was undertaken to determine the effect of the opioid receptor antagonist, naloxone, on the growth of B16 melanoma, a murine tumor known to possess opioid receptors. Naloxone inhibited the growth of B16 melanoma in vitro when monolayer cultures were continuously exposed to concentrations of greater than or equal to 0.25 mg/ml. Tumor cell proliferation as measured by [3H]thymidine ([3H]Tdr) incorporation is reduced by a continuous 48-h treatment with greater than or equal to 0.025 mg/ml but slightly enhanced by a 6-h treatment. The administration of naloxone to mice caused a transient inhibition of subcutaneous local tumor growth at doses of 0.1, 1 and 10 mg/kg daily. At a dose of 10 mg/kg daily, naloxone caused a slight reduction in the number of pulmonary metastases following the intravenous inoculation of tumor cells. The mechanism by which naloxone inhibits tumor growth in vivo is not clear, but factors other than direct cytotoxicity may also be involved. The results further support the role of the endogenous opioid system in the modulation of tumor growth.

Topics: Animals; Cell Division; Cell Line; Lung Neoplasms; Male; Melanoma; Mice; Mice, Inbred C57BL; Naloxone; Neoplasm Transplantation

The antitumor effect of methionine-enkephalin [( Met]enkephalin) was demonstrated in C57BL/6J mice inoculated with B16-BL6 melanoma cells. Local subcutaneous tumor growth was inhibited with a 50-micrograms dose daily for 7 or 14 days. The antitumor effect of [Met]enkephalin was inhibited by the administration of the opioid receptor antagonist naloxone. Naloxone alone had no significant effect on tumor growth.

Topics: Animals; Enkephalin, Methionine; Male; Melanoma; Mice; Mice, Inbred C57BL; Naloxone; Neoplasm Transplantation