Analgesics, Opioid/pharmacology; Lipopolysaccharides/pharmacology; Nerve Tissue Proteins/metabolism; Signal Transduction/drug effects; Toll-Like Receptor 4/metabolism; Analgesics, Opioid/agonists; Analgesics, Opioid/antagonists & inhibitors; Binding, Competitive; Drug Antagonism; Escherichia coli K12/metabolism; Genes, Reporter/drug effects; HEK293 Cells; Humans; Kinetics; Ligands; Lipopolysaccharide Receptors/genetics; Lipopolysaccharide Receptors/metabolism; Lipopolysaccharides/antagonists & inhibitors; Lymphocyte Antigen 96/genetics; Lymphocyte Antigen 96/metabolism; NF-kappa B p50 Subunit/agonists; NF-kappa B p50 Subunit/genetics; NF-kappa B p50 Subunit/metabolism; Narcotic Antagonists/chemistry; Narcotic Antagonists/pharmacology; Nerve Tissue Proteins/agonists; Nerve Tissue Proteins/antagonists & inhibitors; Nerve Tissue Proteins/genetics; Receptors, Opioid, mu/agonists; Receptors, Opioid, mu/antagonists & inhibitors; Receptors, Opioid, mu/metabolism; Recombinant Proteins/agonists; Recombinant Proteins/antagonists & inhibitors; Recombinant Proteins/metabolism; Rhodobacter sphaeroides/metabolism; Toll-Like Receptor 4/agonists; Toll-Like Receptor 4/antagonists & inhibitors; Toll-Like Receptor 4/genetics