Search results for "pyrrolidines"
showing 10 items of 66 documents
Occupancy of striatal D 2 -like dopamine receptors after treatment with the sigma ligand EMD 57445, a putative atypical antipsychotic
1999
Rationale: EMD 57445 (panamesine) is a high affinity sigma ligand with the profile of an atypical antipsychotic in animal studies. It has been reported recently to have antipsychotic activity in schizophrenia. However, its metabolite, EMD 59983, binds also to D2 and D3 dopamine (DA) receptors. Objectives: The aim of this study was to test, using single photon emission computed tomography (SPECT) and [123I]iodobenzamide (IBZM) as the radiotracer, whether EMD 59983 would pass the blood-brain barrier and to what extent it would contribute to the effects of EMD 57445 in schizophrenia. Methods: Two IBZM SPECT-scans were performed in five neuroleptic-free schizophrenic patients (DSM IV), one befo…
Opiate-induced dopamine release is modulated by severity of alcohol dependence: an [(18)F]fallypride positron emission tomography study.
2011
Background Preclinical data implicate the reinforcing effects of alcohol to be mediated by interaction between the opioid and dopamine systems of the brain. Specifically, alcohol-induced release of β-endorphins stimulates μ-opioid receptors (MORs), which is believed to cause dopamine release in the brain reward system. Individual differences in opioid or dopamine neurotransmission have been suggested to be responsible for enhanced liability to abuse alcohol. In the present study, a single dose of the MOR agonist remifentanil was administered in detoxified alcohol-dependent patients and healthy control subjects to mimic the β-endorphin-releasing properties of ethanol and to assess the effect…
Different muscarinic receptor subtypes modulate proliferation of primary human detrusor smooth muscle cells via Akt/PI3K and map kinases.
2013
While acetylcholine (ACh) and muscarinic receptors in the bladder are mainly known for their role in the regulation of smooth muscle contractility, in other tissues they are involved in tissue remodelling and promote cell growth and proliferation. In the present study we have used primary cultures of human detrusor smooth muscle cells (HDSMCs), in order to investigate the role of muscarinic receptors in HDSMC proliferation. Samples were obtained as discarded tissue from men >65 years undergoing radical cystectomy for bladder cancer and cut in pieces that were either immediately frozen or placed in culture medium for the cell culture establishment. HDSMCs were isolated from samples, propagat…
Synthesis of [11C]SSR149415 and preliminary imaging studies using positron emission tomography.
2010
Abstract SSR149415 was the first non-peptide vasopressin-(V1b) receptor antagonist reported. It has been used to probe the role of V1b receptors in animal models of depression, aggression, and stress-anxiety, and was progressed to clinical trials for the treatment of depression. Due to the interest in V1b receptors as a therapeutic target and the growing use of SSR149415 in preclinical research, we developed a method to label SSR145419 with carbon-11 and have studied its pharmacokinetics in non-human primates using positron emission tomography.
Effect of vildagliptin compared to glimepiride on postprandial proinsulin processing in the β cell of patients with type 2 diabetes mellitus
2012
This study compared the effect of Glimepiride versus Vildagliptin on β-cell function and the release of intact proinsulin (PI) in patients with type 2 diabetes mellitus. Patients on metformin monotherapy were randomized to add on treatment with Vildagliptin or Glimepiride. A standardized test meal was given at baseline, after 12 and 24 weeks of treatment. Insulin, PI and blood glucose values were measured in the fasting state and postprandial for 300 min. Fasting PI levels significantly decreased in the Vildagliptin group. The area under the curve for the postprandial release of PI decreased during Vildagliptin and increased during Glimepiride treatment. The proinsulin to insulin ratio decl…
Overexpression of Ogg1 in mammalian cells: effects on induced and spontaneous oxidative DNA damage and mutagenesis
1999
Chinese hamster ovary cell lines (AA8 and AS52) were stably transfected to overexpress hOgg1 protein, the human DNA repair glycosylase for 7,8-dihydro-8-oxoguanine (8-oxoG). In the transfectants, the repair rate of 8-oxoG residues induced by either potassium bromate or the photosensitizer [R]-1-[(10-chloro-4-oxo-3-phenyl-4H-benzo[a]quinolizin-1-yl)-carbo nyl ]-2-pyrrolidinemethanolplus light was up to 3-fold more rapid than in the parental cells. However, the improved repair had little effect on the mutagenicity of potassium bromate in the guanine phosphoribosyl transferase (gpt) locus of the OGG1-transfected AS52 cells. The steady-state (background) levels of DNA base modifications sensiti…
Atropine-resistant effects of the muscarinic agonists McN-A-343 and AHR 602 on cardiac performance and the release of noradrenaline from sympathetic …
1974
Abstract 1 The effects of 4-(m-chlorophenylcarbamoyloxy)-2-butynyltrimethylammonium chloride (McN-A-343) and N-benzyl-3-pyrrolidyl acetate methobromide (AHR 602) on cardiac performance and noradrenaline release from terminal sympathetic fibres were measured in isolated perfused hearts of rabbits. 2 In the presence of sufficient atropine to block muscarinic receptors, high concentrations of McN-A-343 and AHR 602 caused no cardiac stimulation and there was no increase in the resting output of noradrenaline into the perfusates. 3 McN-A-343 and AHR 602 increased both the mechanical responses and the transmitter overflow evoked by electrical stimulation of the sympathetic nerves (SNS) but inhibi…
Safety and Pharmacokinetics of Glecaprevir/Pibrentasvir in Adults With Chronic Genotype 1–6 Hepatitis C Virus Infections and Compensated Liver Disease
2019
Background: Untreated, chronic hepatitis C virus (HCV) infection may lead to progressive liver damage, which can be mitigated by successful treatment. This integrated analysis reports the safety, efficacy, and pharmacokinetics (PK) of the ribavirin-free, direct-acting, antiviral, fixed-dose combination of glecaprevir/pibrentasvir (G/P) in patients with chronic HCV genotype 1-6 infections and compensated liver disease, including patients with chronic kidney disease stages 4 or 5 (CKD 4/5). Methods: Data from 9 Phase II and III clinical trials, assessing the efficacy and safety of G/P treatment for 8-16 weeks, were included. The presence of cirrhosis was determined at screening using a liver …
Safety and efficacy of a fixed-dose combination regimen of grazoprevir, ruzasvir, and uprifosbuvir with or without ribavirin in participants with and…
2017
Background There is a need for hepatitis C virus (HCV) therapies with excellent efficacy across genotypes and in diverse populations. Part A of the C-CREST-1 and C-CREST-2 trials led to the selection of a three-drug regimen of grazoprevir (MK-5172; an HCV NS3/4A protease inhibitor; 100 mg/day) plus ruzasvir (MK-8408; an NS5A inhibitor; 60 mg/day) plus uprifosbuvir (MK-3682; an HCV NS5B polymerase inhibitor; 450 mg/day). Part B of the studies tested this combination as a single formulation in different treatment durations in a broader population. Methods Part B of these randomised, phase 2, open-label clinical trials enrolled individuals from 15 countries who were chronically infected with H…
Synthesis of 8-aminomorphans with high KOR affinity
2021
2-Azabicyclo[3.3.1]nonanes (morphans) with a (3,4-dichlorophenyl)acetyl group at 2-position and a pyrrolidino moiety at 8-position were designed as conformationally restricted analogs of piperidine-based KOR agonists. The synthesis started with 4-oxopiperidine-2-carboxylic acid comprising 13 reaction steps. At first the ketone 10 was transformed into diester 7 bearing a propionate side chain. Dieckmann condensation of diester 7 to afford bicyclic enolester 14 and subsequent Krapcho deethoxycarbonylation represent the key steps of the synthesis. The enantiomeric pyrrolidines (1S,5R,8R)-5a and (1R,5S,8S)-5a were separated by chiral HPLC. The eutomer (1S,5R,8R)-5a showed high KOR affinity (K-i…