The aim of this work was to study effects of ketotifen fumarate (KF) on prevention of tissue damage in testes of rats with experimental autoimmune orchitis (EAO) and on the contralateral testis in a model of prolonged testicular cord torsion (TCT). Rats with EAO or TCT were injected intraperitoneally once daily with KF or saline solution (vehicle group). Incidence and severity of testicular damage were evaluated by histopathology using an EAO score or a Johnsen score. Mast cells (MC) were identified by histochemistry and quantified. In EAO model, KF significantly reduced severity of histopathological testicular damage compared to rats in the vehicle group. KF also reduced the number of testicular MC compared to vehicle group. Similarly, in TCT model, multifocal damage of the contralateral testis was observed 30 days after testicular torsion characterized by sloughing of the germinal epithelium, seminiferous tubule atrophy, and interstitial edema. Focal signs of inflammation and fibrosis of seminiferous tubular walls were also observed. In contrast, sections of contralateral testis of rats injected with KF and killed 30 days after surgery showed normal histological features. A significant decrease in the number of MC was observed in rats treated with KF compared to untreated animals. In conclusion, we demonstrated that treatment with KF reduced testicular inflammatory process and MC infiltrates in both EAO and TCT models. The results suggest a promising treatment for infertile male patients with testicular pathologies associated with inflammation and germ cell loss.
Animals ; Autoimmune Diseases/pathology* ; Cell Count ; Epididymis/pathology* ; Epididymitis/pathology* ; Histamine H1 Antagonists/pharmacology* ; Hypersensitivity, Delayed ; Immunity, Cellular/drug effects* ; Ketotifen/pharmacology* ; Male ; Mast Cells/pathology* ; Orchitis/pathology* ; Rats ; Severity of Illness Index ; Spermatic Cord Torsion/pathology* ; Testis/pathology* ; Vaccination

Spinal α-motoneurons directly innervate skeletal muscles and function as the final common path for movement and behavior. The processes that determine the excitability of motoneurons are critical for the execution of motor behavior. In fact, it has been noted that spinal motoneurons receive various neuromodulatory inputs, especially monoaminergic one. However, the roles of histamine and hypothalamic histaminergic innervation on spinal motoneurons and the underlying ionic mechanisms are still largely unknown. In the present study, by using the method of intracellular recording on rat spinal slices, we found that activation of either H or H receptor potentiated repetitive firing behavior and increased the excitability of spinal α-motoneurons. Both of blockage of K channels and activation of Na-Ca exchangers were involved in the H receptor-mediated excitation on spinal motoneurons, whereas the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels were responsible for the H receptor-mediated excitation. The results suggest that, through switching functional status of ion channels and exchangers coupled to histamine receptors, histamine effectively biases the excitability of the spinal α-motoneurons. In this way, the hypothalamospinal histaminergic innervation may directly modulate final motor outputs and actively regulate spinal motor reflexes and motor execution.
Animals ; Histamine ; pharmacology ; Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels ; metabolism ; Motor Neurons ; drug effects ; physiology ; Rats ; Receptors, Histamine H2 ; metabolism ; Sodium-Calcium Exchanger ; metabolism

The ventral pallidum (VP) is a crucial component of the limbic loop of the basal ganglia and participates in the regulation of reward, motivation, and emotion. Although the VP receives afferent inputs from the central histaminergic system, little is known about the effect of histamine on the VP and the underlying receptor mechanism. Here, we showed that histamine, a hypothalamic-derived neuromodulator, directly depolarized and excited the GABAergic VP neurons which comprise a major cell type in the VP and are responsible for encoding cues of incentive salience and reward hedonics. Both postsynaptic histamine H1 and H2 receptors were found to be expressed in the GABAergic VP neurons and co-mediate the excitatory effect of histamine. These results suggested that the central histaminergic system may actively participate in VP-mediated motivational and emotional behaviors via direct modulation of the GABAergic VP neurons. Our findings also have implications for the role of histamine and the central histaminergic system in psychiatric disorders.
Action Potentials ; drug effects ; Animals ; Basal Forebrain ; cytology ; Dimaprit ; pharmacology ; Dose-Response Relationship, Drug ; Electric Stimulation ; Female ; GABAergic Neurons ; drug effects ; Histamine ; pharmacology ; Histamine Agonists ; pharmacology ; Lysine ; analogs & derivatives ; metabolism ; Male ; Patch-Clamp Techniques ; Pyridines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptors, Histamine H1 ; metabolism ; Receptors, Histamine H2 ; metabolism ; Sodium Channel Blockers ; pharmacology ; Tetrodotoxin ; pharmacology ; gamma-Aminobutyric Acid ; metabolism

Cyproheptadine (CPH), a first-generation antihistamine, enhances the delayed rectifier outward K current (I) in mouse cortical neurons through a sigma-1 receptor-mediated protein kinase A pathway. In this study, we aimed to determine the effects of CPH on neuronal excitability in current-clamped pyramidal neurons in mouse medial prefrontal cortex slices. CPH (10 µmol/L) significantly reduced the current density required to generate action potentials (APs) and increased the instantaneous frequency evoked by a depolarizing current. CPH also depolarized the resting membrane potential (RMP), decreased the delay time to elicit an AP, and reduced the spike threshold potential. This effect of CPH was mimicked by a sigma-1 receptor agonist and eliminated by an antagonist. Application of tetraethylammonium (TEA) to block I channels hyperpolarized the RMP and reduced the instantaneous frequency of APs. TEA eliminated the effects of CPH on AP frequency and delay time, but had no effect on spike threshold or RMP. The current-voltage relationship showed that CPH increased the membrane depolarization in response to positive current pulses and hyperpolarization in response to negative current pulses, suggesting that other types of membrane ion channels might also be affected by CPH. These results suggest that CPH increases the excitability of medial prefrontal cortex neurons by regulating TEA-sensitive I channels as well as other TEA-insensitive K channels, probably I and inward-rectifier Kir channels. This effect of CPH may explain its apparent clinical efficacy as an antidepressant and antipsychotic.
Animals ; Cyproheptadine ; pharmacology ; Female ; Histamine H1 Antagonists ; pharmacology ; Membrane Potentials ; drug effects ; physiology ; Mice, Inbred C57BL ; Patch-Clamp Techniques ; Potassium Channel Blockers ; pharmacology ; Potassium Channels ; metabolism ; Prefrontal Cortex ; drug effects ; physiology ; Pyramidal Cells ; drug effects ; physiology ; Receptors, sigma ; agonists ; metabolism ; Tetraethylammonium ; pharmacology ; Tissue Culture Techniques

To investigate the effects of neuronal histamine on spatial memory acquisition impairment in rats with pentylenetetrazole-kindling epilepsy, and to explore its mechanisms.A subconvulsive dose of pentylenetetrazole (35 mg/kg) was intraperitoneally injected in rats every 48 h to induce chemical kindling until fully kindled. Morris water maze was used to measure the spatial memory acquisition of the rats one week after fully pentylenetetrazole-kindled, and the histamine contents in different brain areas were measured spectrofluorometrically. Different dosages of hitidine (the precursor of histamine), pyrilamine (H1 receptor antagonist), and zolantidine (H2 receptor antagonist) were intraperitoneally injected, and their effects on spatial memory acquisition of the rats were observed.Compared with control group, escape latencies were significantly prolonged on Morris water maze training day 2 and day 3 in pentylenetetrazole-kindling epilepsy rats (all<0.05); and the histamine contents in hippocampus, thalamus and hypothalamus were decreased significantly (all<0.05). Escape latencies were markedly shortened on day 3 by intraperitoneally injected with histidine 500 mg/kg, and on day 2 and day 3 by intraperitoneally injected with histidine 1000 mg/kg in pentylenetetrazole-kindling epilepsy rats (all<0.05). The protection of histidine was reversed by zolantidine (10 and 20 mg/kg), but not by pyrilamine.Neuronal histamine can improve the spatial memory acquisition impairment in rats with pentylenetetrazole-kindling epilepsy, and the activation of H2 receptors is possibly involved in the protective effects of histamine.
Animals ; Benzothiazoles ; pharmacology ; Brain Chemistry ; drug effects ; Epilepsy ; chemically induced ; complications ; Hippocampus ; chemistry ; Histamine H1 Antagonists ; pharmacology ; Histamine H2 Antagonists ; pharmacology ; Histidine ; pharmacology ; Hypothalamus ; chemistry ; Kindling, Neurologic ; physiology ; Memory Disorders ; drug therapy ; etiology ; Pentylenetetrazole ; Phenoxypropanolamines ; pharmacology ; Piperidines ; pharmacology ; Pyrilamine ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptors, Histamine H2 ; drug effects ; physiology ; Spatial Memory ; drug effects ; Spectrometry, Fluorescence ; Thalamus ; chemistry

Mast cells and basophils are multifunctional effector cells that contain abundant secretory granules in their cytoplasm. Both cell types are involved in a variety of inflammatory and immune events, producing an array of inflammatory mediators, such as cytokines. The aim of the study was to examine whether isoquercitrin modulates allergic and inflammatory reactions in the human basophilic KU812 cells and to elucidate its influence on the phosphorylation of mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-κB activation. The KU812 cells were stimulated with phorbol-12-myristate 13-acetate plus the calcium ionophore A23187 (PMACI). The inhibitory effects of isoquercitrin on the productions of histamine and pro-inflammatory cytokines in the stimulated KU812 cells were measured using cytokine-specific enzyme-linked immunosorbent (ELISA) assays. Western blotting analysis was used to assess the effects of isoquercitrin on the MAPKs and NF-κB protein levels. Our results indicated that the isoquercitrin treatment of PMACI-stimulated KU812 cells significantly reduced the production of histamine and the pro-inflammatory cytokines, such as interleukin (IL)-6, IL-8, IL-1β, and tumor necrosis factor (TNF)-α. The treated cells exhibited decreased phosphorylation of extracellular signal-regulated kinase (ERK), revealing the role of ERK MAPK in isoquercitrin-mediated allergy inhibition. Furthermore, isoquercitrin suppressed the PMACI-mediated activation of NF-κB in the human basophil cells. In conclusion, the results from the present study provide insights into the potential therapeutic use of isoquercitrin for the treatment of inflammatory and allergic reactions.
Basophils ; drug effects ; immunology ; Cytokines ; genetics ; immunology ; Down-Regulation ; drug effects ; Extracellular Signal-Regulated MAP Kinases ; genetics ; immunology ; Histamine ; immunology ; Humans ; Hypersensitivity ; drug therapy ; genetics ; immunology ; NF-kappa B ; genetics ; immunology ; Quercetin ; analogs & derivatives ; pharmacology

To investigate me material basis of Mahuang Fuzi Xixin decoction (MFXD) for anti-inflammation and immune-suppression based on the combined method of serum chemical and serum pharmacological. The LC-MS/MS fingerprints of MFXD, drug-containing serum and blank serum were compared to define the components in plasma. Histamine, β-hexosaminidase released from RBL-2H3 cell infulenced by drug-containing serum at different time points were measured by ELISA. The effect of drug-containing serum on lipopolysaccharide-induced splenocyte proliferation at different time points were determined by MTT. A correlation analysis was made on components of MFXD and pharmacological indexes based the stepwise regression method. After the intragastrical administration with MFXD, 32 components were discovered in rat serum, including 27 prototype components (10 from Mahuang, 13 from Fuzi and four from Xixin) and five unknown components. Compared with blank serum, drug-containing serum could reduce the release of histamine from RBL-2H3 induced by antigen at different time points (P < 0.05); except the 4-hour drug-containing serum, all of the remaining drug-containing serums could inhibit the RBL-2H3 mastocyte degranulation induced by antigen at different time points (P < 0.05). Drug-containing serum could significantly lipopolysaccharide-induced mouse splenocyte proliferation at 15 and 30 min (P < 0.05). A regression analysis was made on the chemical data of components absorbed into blood and pharmacological indexes, i. e. release rate of histamine, release rate of β-hexosaminidase and inhibition rate of splenocyte. This suggested the close correlations among methyl pseudo-ephedrine, pseudoephedrine and histamine released from RBL-2H3 induced by antigen; pseudoephedrine, hypaconine, methyl pseudoephedrine and β-hexosaminidase released from RBL-2H3 induced by antigen; as well as benzoyl hypaconine, benzoylaconine, 14-benzoyl-10-OH-mesaconine, mesaconine and lipopolysaccharide-induced mouse splenocyte proliferation. Methylpseudoephedrine, pseudoephedrine, benzoyl hypaconine, benzoylaconine and mesaconine may be part of material basis of MFXD on anti-inflammation and immune suppression.
Animals ; Anti-Inflammatory Agents ; chemistry ; pharmacology ; Cell Degranulation ; drug effects ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; Female ; Histamine ; immunology ; Immunosuppressive Agents ; chemistry ; pharmacology ; Male ; Mass Spectrometry ; Mast Cells ; drug effects ; immunology ; Mice ; Rats ; Rats, Wistar ; Serum ; chemistry

This study is to investigate the inhibitory effect of kaempferol on inflammatory response of lipopolysaccharide(LPS)-stimulated HMC-1 mast cells. The cytotoxicity of kaempferol to HMC-1 mast cells were analyzed by using MTT assay and then the administration concentrations of kaempferol were established. Histamine, IL-6, IL-8, IL-1β and TNF-α were measured using ELISA assay in activated HMC-1 mast cells after incubation with various concentrations of kaempferol (10, 20 and 40 µmol.L-1). Western blot was used to test the protein expression of p-IKKβ, IκBα, p-IκBα and nucleus NF-κB of LPS-induced HMC-1 mast cells after incubation with different concentrations of kaempferol. The optimal concentrations of kaempferol were defined as the range from 5 µmol.L-1 to 40 µmol.L-1. Kaempferol significantly decreased the release of histamine, IL-6, IL-8, IL-1β and TNF-α of activated HMC-1 mast cells (P<0.01). After incubation with kaempferol, the protein expression of p-IKKβ, p-IKBa and nucleus NF-κB (p65) markedly reduced in LPS-stimulated HMC-1 mast cells (P<0.01). Taken together, we concluded that kaempferol markedly inhibit mast cell-mediated inflammatory response. At the same time, kaempferol can inhibit the activation of IKKβ, block the phosphorylation of IκBα, prevent NF-KB entering into the nucleus, and then decrease the release of inflammatory mediators.
Cells, Cultured ; Histamine ; metabolism ; Humans ; I-kappa B Kinase ; metabolism ; I-kappa B Proteins ; metabolism ; Inflammation ; metabolism ; Interleukin-1beta ; metabolism ; Interleukin-6 ; metabolism ; Interleukin-8 ; metabolism ; Kaempferols ; pharmacology ; Lipopolysaccharides ; Mast Cells ; drug effects ; NF-KappaB Inhibitor alpha ; NF-kappa B ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVE: The goal of this study was to study the mechanism of substance P (SP)-mediated the neural control of mast cell (MC) degranulation. METHOD: Bone marrow mast cells from mice were cultured with stem cell factor (SCF), IL-3 and IL-4 (group A) and SCF, IL-3 (group B) for four weeks. Then the cells were harvested and reserved for studies. Western Blot hybridization technique was used to detect the expression of FcεR I α and NK-1R on MCs from the two groups. Then such cells were activated with SP (0, 0. 01, 0. 10, 1. 00, 10. 00 µg/ml, respectively) for 30 min. The histamine released into the supernatant and stored in the protoplasm was quantified by enzyme linked immunosorbent assay (ELISA). And the percentage of histamine release was calculated as a percent of total histamine content. RESULT: The expressions of FcεR I α and NK-1R on these mast cells in group A were statistically higher than in group B (P<0. 05). The MCs from two groups can be actived when stimulated by SP, but the level of MC degranulation in group A was higher than group B (P<0. 05). CONCLUSION Neuropeptide may stimulate MC degranulation through immunological and non-immunological pathways. In summary, the current study provides us with better understanding of the mechanism of neuropeptide-controlled MC deranulation, and this should be helpful for the further research involved in the mechanism and treatmemt of airway hyper-reactivity.
Animals ; Bone Marrow Cells ; Cell Degranulation ; Cells, Cultured ; Culture Media ; chemistry ; Histamine ; metabolism ; Interleukin-3 ; pharmacology ; Interleukin-4 ; pharmacology ; Mast Cells ; cytology ; metabolism ; Mice ; Stem Cell Factor ; pharmacology ; Substance P ; pharmacology

Primary health care providers play a critical role in maintaining public health, and the appropriate use of pharmaceutical products is one of the major parts of their practice. This series of articles, entitled 'Clinical Pharmacology Review for Primary Health Care Providers,' is intended to help primary health care providers select more appropriate prescriptions for frequently used drugs based on up-to-date information. We expect that this effort will contribute to improvements in public health and diminish unnecessary drug use.
Histamine Antagonists* ; Pharmaceutical Preparations ; Pharmacology ; Pharmacology, Clinical* ; Prescriptions ; Primary Health Care* ; Public Health