Journal of pharmacological sciences
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Our previous study indicated that 071031B, a novel potential serotonin and norepinephrine reuptake inhibitor, showed robust antidepressant activity in multiple depression models, and could simultaneously inhibit 5-HT and NE reuptake in vitro. The present study was to evaluate the effects of 071031B on monoamine system in vivo, by using pharmacological models, including 5-HTP induced head-twitch test, yohimbine toxicity potentiation test, and reserpine induced hypothermia test, and determining monoamine transmitter levels in reserpine induced monoamine depletion model or chronic unpredictable stress (CUS) model. ⋯ Further monoamine assays demonstrated that acute or chronic administration of 071031B at 10 or 20 mg/kg increased 5-HT and/or NE levels in various brain regions in reserpine or CUS induced monoamine depletion models, respectively, without effect on DA and its metabolites. Our results revealed that 071031B produces potent inhibition of 5-HT and NE reuptake in vivo.
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Bortezomib, an effective anticancer drug for multiple myeloma, often causes peripheral neuropathy which is mainly characterized by numbness and painful paresthesia. Nevertheless, there is no effective strategy to escape or treat bortezomib-induced peripheral neuropathy (BIPN), because we have understood few mechanism of this side effect. In this study, we evaluated behavioral and pathological characteristics of BIPN, and investigated pharmacological efficacy of various analgesic drugs and adjuvants on mechanical allodynia induced by bortezomib treatment in rats. ⋯ Furthermore, the exposure to bortezomib shortened neurite length in PC12 cells. Finally, the result of evaluation of anti-allodynic potency, oral administration of tramadol (10 mg/kg), pregabalin (3 mg/kg), duloxetine (30 mg/kg) or mexiletine (100 mg/kg), but not amitriptyline or diclofenac, transiently relieved the mechanical allodynia induced by bortezomib. These results suggest that axonal degeneration of the sciatic nerve is involved in BIPN and that some analgesic drugs and adjuvants are effective in the relief of painful neuropathy.
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An association between postoperative analgesic requirements in subjects who underwent orthognathic surgery and the rs1465040 single-nucleotide polymorphism close to the transient receptor potential subfamily C member 3 (TRPC3) gene was suggested by our previous genome-wide association study. To verify this association, we analyzed the association between the rs1465040 SNP and analgesic requirements, including opioid requirements, after open abdominal surgery. The association between the rs1465040 SNP and postoperative analgesic requirements was confirmed in the open abdominal surgery group (P = 0.036), suggesting that the TRPC3 SNP may contribute to predicting postoperative analgesic requirements.
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Cav3.2 T-type Ca(2+) channels targeted by H2S, a gasotransmitter, participate in cyclophosphamide-induced cystitis and bladder pain. Given that zinc selectively inhibits Cav3.2 among T-channel isoforms and also exhibits antioxidant activity, we examined whether polaprezinc (zinc-l-carnosine), a medicine for peptic ulcer treatment and zinc supplementation, reveals preventive or therapeutic effects on bladder inflammation and/or pain in the mouse with cyclophosphamide-induced cystitis, a model for interstitial cystitis. Systemic administration of cyclophosphamide caused cystitis-related symptoms including increased bladder weight and vascular permeability, and histological signs of bladder edema, accompanied by bladder pain-like nociceptive behavior/referred hyperalgesia. ⋯ The same dose of polaprezinc also prevented the increased malondialdehyde level, an indicator of lipid peroxidation, and protein upregulation of cystathionine-γ-lyase, an H2S-generating enzyme, but not occludin, a tight junction-related membrane protein, in the bladder tissue of cyclophosphamide-treated mice. Oral posttreatment with polaprezinc at 30-100 mg/kg reversed the nociceptive behavior/referred hyperalgesia in a dose-dependent manner without affecting the increased bladder weight. Together, our data show that zinc supplementation with polaprezinc prevents the cyclophosphamide-induced cystitis probably through the antioxidant activity, and, like T-channel blockers, reverses the established cystitis-related bladder pain in mice, suggesting novel therapeutic usefulness of polaprezinc.
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A hybrid pharmacokinetic/pharmacodynamic (PK/PD) model with extended-release (ER) process and target mediated drug disposition (TMDD) was developed for exenatide ER to account for its complex absorption process and glucagon-like peptide 1 receptor (GLP-1R)-mediated non-linear PK behaviors along with its influences to fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c). Using hybrid PK/PD model, simulations were done to explore the potential dosing regimens which could achieve likelihood of more pharmacodynamic exposure with respect to FPG and HbA1c over a much shorter period compared with the currently used treatment protocol. ⋯ Monte Carlo simulation was applied to mimic the PK profiles when higher loading dose 7.5 and 5.0 mg exenatide ER were subcutaneously administrated with different dosing intervals at the first 3 weeks of 30-week treatment. Two potentially optimizing schedules could improve the likelihood of achieving much more FPG and HbA1c exposures than currently used clinical treatment protocol.