77 research outputs found
House of Commons Library: Briefing paper: Number 07147, 13 April 2018: School places in England: applications, allocations and appeals
Background: We previously reported that ginsenoside Re (GRe) attenuated against methamphetamine (MA)-induced neurotoxicity via anti-inflammatory and antioxidant potentials. We also demonstrated that dynorphin possesses anti-inflammatory and antioxidant potentials against dopaminergic loss, and that balance between dynorphin and substance P is important for dopaminergic neuroprotection. Thus, we examined whether GRe positively affects interactive modulation between dynorphin and substance P against MA neurotoxicity in mice.
Methods: We examined changes in dynorphin peptide level, prodynorphin mRNA, and substance P mRNA, substance P-immunoreactivity, homeostasis in enzymatic antioxidant system, oxidative parameter, microglial activation, and pro-apoptotic parameter after a neurotoxic dose of MA to clarify the effects of GRe, prodynorphin knockout, pharmacological inhibition of κ-opioid receptor (i.e., nor-binaltorphimine), or neurokinin 1 (NK1) receptor (i.e., L-733,060) against MA insult in mice.
Results: GRe attenuated MA-induced decreases in dynorphin level, prodynorphin mRNA expression in the striatum of wild-type (WT) mice. Prodynorphin knockout potentiated MA-induced dopaminergic toxicity in mice. The imbalance of enzymatic antioxidant system, oxidative burdens, microgliosis, and pro-apoptotic changes led to the dopaminergic neurotoxicity. Neuroprotective effects of GRe were more pronounced in prodynorphin knockout than in WT mice. Nor-binaltorphimine, a κ-opioid receptor antagonist, counteracted against protective effects of GRe. In addition, we found that GRe significantly attenuated MA-induced increases in substance P-immunoreactivity and substance P mRNA expression in the substantia nigra. These increases were more evident in prodynorphin knockout than in WT mice. Although, we observed that substance P-immunoreactivity was co-localized in NeuN-immunreactive neurons, GFAP-immunoreactive astrocytes, and Iba-1-immunoreactive microglia. NK1 receptor antagonist L-733,060 or GRe selectively inhibited microgliosis induced by MA. Furthermore, L-733,060 did not show any additive effects against GRe-mediated protective activity (i.e., antioxidant, antimicroglial, and antiapoptotic effects), indicating that NK1 receptor is one of the molecular targets of GRe.
Conclusions: Our results suggest that GRe protects MA-induced dopaminergic neurotoxicity via upregulatgion of dynorphin-mediated κ-opioid receptor and downregulation of substance P-mediated NK1 R
Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial
Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie
The role of striatal G alpha(q/11) protein in methamphetamine-induced behavioral sensitization in mice
G alpha(q/11) protein transducer signals from neurotransmitter receptors and has been implicated in several functions of the central nervous system. In this study, the role of G alpha(q/11) protein in methamphetamine (METH)-induced behavioral sensitization was investigated using neurochemical and behavioral approaches. Repeated treatment with METH (2 mg/kg, intraperitoneally) significantly increased behavioral sensitization as well as G alpha(q/11) protein expression and G alpha protein activity in the striata of mice, while a single treatment of METH at the same dose did not affect these parameters. Repeated intrastriatal injections of a G alpha(q/11) inhibitor, [D-Trp7,9,10]-substance P, significantly reduced behavioral sensitization and striatal dopamine (DA) level in response to METH, with no effect on striatal tyrosine hydroxylase expression. These results suggest that G alpha(q/11) protein facilitates METH-induced behavioral sensitization by modulating DA release in the mouse striatum
© 2017 Elsevier B.V. All rights reserve
Designer Drug, 25D-NBOMe, Has Reinforcing and Rewarding Effects through Change of a Dopaminergic Neurochemical System
2-(2,5-Dimethoxy-4-methylphenyl)-N-(2-methoxybenzyl)_ethanamine
(25D-NBOMe), an analogue
of the 2C family, is a newly synthesized psychoactive substance. It
acts as an agonist at the 5-HT2A receptor and has a similar
mechanism to that of NBOMe compounds. However, the pharmacological
mechanism for its rewarding and reinforcing effects has not been revealed.
In the present study, intravenous self-administration (IVSA) test
and conditioned place preference (CPP) test were performed to investigate
whether 25D-NBOMe has abuse potential. We also evaluated the effects
of 25D-NBOMe on neurochemical changes using western blot analysis
and microdialysis. The IVSA test revealed increased self-administration
in 25D-NBOMe (0.03 mg/kg)-treated rats. In addition, the CPP test
revealed rewarding effects in 25D-NBOMe (1 mg/kg)-treated mice. In
the neurochemical studies, 25D-NBOMe treatment affected the expression
of dopamine (DA) receptor D1 (DRD1), DA receptor D2 (DRD2), tyrosine
hydroxylase, DA transporter (DAT), and phospho-DAT (p-DAT) in the nucleus accumbens (NAc). In addition, microdialysis
revealed that treatment with progressively increasing doses (1, 3,
and 10 mg/kg) of 25D-NBOMe increased the extracellular levels of DA,
3,4-dihydroxyphenylacetic acid, and homovanillic acid in the rat NAc.
Taken together, our results show the abuse potential and neurochemical
changes related to addictive behavior after administration of 25D-NBOMe
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