Search results for "OTR"
showing 10 items of 6791 documents
Concomitant gonadotropin-releasing hormone agonist and menotropin treatment for the synchronized induction of multiple follicles.
1988
In an effort to overcome possible interference by endogenous gonadotropin-ovarian hormone dynamics, desensitization of the pituitary gonadotropins by a gonadotropin-releasing hormone agonist (GnRHa) was achieved in 12 women with repeatedly failed attempts at multiple follicular stimulation. Eight women were scheduled for in vitro fertilization (IVF) and embryo transfer (ET), and 4 for gamete intrafallopian transfer (GIFT). Stimulation failure was characterized by premature luteinization, poor estradiol (E2) response, or inadequate follicular growth. The agonist was administered by nasal spray 500 to 600 micrograms/day beginning on days 21 to 23 of the menstrual cycle. A rapid desensitizatio…
Similar endometrial development in oocyte donors treated with either high- or standard-dose GnRH antagonist compared to treatment with a GnRH agonist…
2005
Background This descriptive study evaluates the impact on endometrial development of standard and high doses of a GnRH antagonist in stimulated cycles compared with GnRH agonist and natural cycles. Methods Thirty-one oocyte donors were treated with a combination of rFSH and 0.25 mg/day ganirelix (standard dose), 2 mg/day ganirelix (high dose) or 0.6 mg/day buserelin (long protocol). Vaginal progesterone (200 mg/day) was administered in the luteal phase. Endometrial biopsies were performed 2 and 7 days after HCG administration. Additional biopsies were carried out in a subset of 12 subjects, 2 and 7 days following the LH peak of their previous natural cycle. Biopsies were evaluated histologi…
Chapter 9 Nicotinic acetylcholine receptors on hippocampal neurons: cell compartment-specific expression and modulatory control of channel activity
1996
Publisher Summary The neuronal nicotinic acetylcholine receptors (nAChRs) are differentially expressed on the somato-dendritic surface of hippocampal neurons. This chapter demonstrates that various ions and drugs play a crucial role in modulating the activity of neuronal nAChRs. Considering the diversity of the neurotransmitter receptors and their binding sites and the diversity of substances, which can act simultaneously as a primary agonist of one receptor and an allosteric modulator of a different receptor, an enormous variety of combinatorial possibilities can be achieved in the brain giving rise to very complex neuronal networks. The characterization of the diversity of many receptors …
Histaprodifens: synthesis, pharmacological in vitro evaluation, and molecular modeling of a new class of highly active and selective histamine H(1)-r…
2000
A new class of histamine analogues characterized by a 3, 3-diphenylpropyl substituent at the 2-position of the imidazole nucleus has been prepared outgoing from 4,4-diphenylbutyronitrile (4b) via cyclization of the corresponding methyl imidate 5b with 2-oxo-4-phthalimido-1-butyl acetate or 2-oxo-1,4-butandiol in liquid ammonia, followed by standard reactions. The title compounds displayed partial agonism on contractile H(1) receptors of the guinea-pig ileum and endothelium-denuded aorta, respectively, except 10 (histaprodifen; 2-[2-(3, 3-diphenylpropyl)-1H-imidazol-4-yl]ethanamine) which was a full agonist in the ileum assay. While 10 was equipotent with histamine (1), methylhistaprodifen (…
Pretreatment with gonadotropin-releasing hormone (GnRH) antagonists to prevent the flare-up effect of long-acting GnRH agonists: results of a pilot s…
2007
This study evaluated in vivo whether the flare-up effect of GnRH agonists can be suppressed through pretreatment with a GnRH antagonist. The classic flare-up effect caused by 3.8 mg goserelin acetate could not be suppressed through pretreatment using a single dosage of 3.24 mg cetrorelix acetate.
Anxiolytic-like effects of acute and chronic GABA transporter inhibition in rats.
2002
Acute GABA transporter inhibition can induce anxiolytic-like behaviors. The present analysis addressed whether chronic treatment (23 days via drinking water) with a GABA transporter inhibitor affects rat behavior similar to acute treatment and interferes with additional benzodiazepine-receptor agonistic treatment. Seventy-one rats divided into seven groups were acutely treated with either vehicle, diazepam (2 mg/kg), zolpidem (0.05 mg/kg), tiagabine (19 mg/kg) or chronically with tiagabine with or without acute diazepam or zolpidem. Animals were behaviorally characterized in an elevated plus-maze. None of the treatments induced changes in the activity of the animals. Acute and chronic treat…
Intra-Nasally Administered Oligopeptide Lunasin Acts as a Possible Anti-Psychotic Agent in Mice Models
2019
Background and Objectives: Previously we have shown that synthetic lunasin, a 43 amino acid residue-containing peptide, after its central (intracisternal) administration in mice demonstrated antagonism against dopaminergic drug behavioural effects, indicating a putative antipsychotic/anti-schizophrenic profile of lunasin. The aims of the present studies were: to test whether lunasin would show an influence on the dopaminergic system after intranasal administration, and to examine the effect(s) of lunasin on serotonin and glutamatergic systems, which could play an essential role in antipsychotic action. Materials and Methods: Lunasin was administered intra-nasally at doses 0.1 and 1 nmol/mou…
Exploring kainate receptor pharmacology using molecular dynamics simulations.
2010
Ionotropic glutamate receptors (iGluRs) are enticing targets for pharmaceutical research; however, the search for selective ligands is a laborious experimental process. Here we introduce a purely computational procedure as an approach to evaluate ligand–iGluR pharmacology. The ligands are docked into the closed ligand-binding domain and during the molecular dynamics (MD) simulation the bi-lobed interface either opens (partial agonist/antagonist) or stays closed (agonist) according to the properties of the ligand. The procedure is tested with closely related set of analogs of the marine toxin dysiherbaine bound to GluK1 kainate receptor. The modeling is set against the abundant binding data …
Choline is a Selective Agonist of α7 Nicotinic Acetylcholine Receptors in the Rat Brain Neurons
1998
In the present study, we demonstrate that choline, a precursor of acetylcholine (ACh) and a product of acetylcholine hydrolysis by acetylcholinesterase (AChE), acts as an efficient and relatively selective agonist of alpha7-containing nicotinic acetylcholine receptors (nAChR) in neurons cultured from the rat hippocampus, olfactory bulb and thalamus as well as in PC12 cells. Choline was able to activate postsynaptic and presynaptic alpha7 nAChRs, with the latter action resulting in the release of other neurotransmitters. Although choline was approximately one order of magnitude less potent than ACh (EC50 of 1.6 mM for choline and 0.13 mM for ACh), it acted as a full agonist at alpha7 nAChRs.…
Structural Mechanism of N-Methyl-D-Aspartate Receptor Type 1 Partial Agonism
2012
N-methyl-D-aspartate (NMDA) receptors belong to a family of ionotropic glutamate receptors that contribute to the signal transmission in the central nervous system. NMDA receptors are heterotetramers that usually consist of two GluN1 and GluN2 monomers. The extracellular ligand-binding domain (LBD) of a monomer is comprised of discontinuous segments that form the functional domains D1 and D2. While the binding of a full agonist glycine to LBD of GluN1 is linked to cleft closure and subsequent ion-channel opening, partial agonists are known to activate the receptor only sub-maximally. Although the crystal structures of the LBD of related GluA2 receptor explain the mechanism for the partial a…