Search results for "RECEPTORS"
showing 10 items of 3254 documents
Raloxifene increases proliferation of human endothelial cells in association with increased gene expression of cyclins A and B1.
2006
Objective To examine the proliferative effect of of raloxifene on human umbilical-vein endothelial cells (HUVECs), and to investigate whether there is an associated increased expression of some key regulators of the cell cycle. Design Cell culture for different incubation times. Setting University research laboratory. Patient(s) Sources of HUVECs. Intervention(s) Measurement of cell proliferation, of protein levels of cyclin A, cyclin B1, cyclin D1, cyclin-dependent protein kinase (CDK) 2, CDK4, and p27 Kip1 , and of messenger RNA expression of cyclin A, cyclin B1, and p27 Kip1 . Main Outcome Measure(s) Cell proliferation was measured by the 3-(4.5-dimethylthiazol-2-yl)-2,5-diphenyltetrazol…
Gathering of aging and estrogen withdrawal in vascular dysfunction of senescent accelerated mice.
2010
The aim of this work was to characterize a mouse model of experimental menopause and cardiovascular aging that closely reflects menopause in women. Senescence accelerated mouse (SAM)-Resistant type 1 (SAMR1, n=30) and SAM-Prone type 8 (SAMP8, n=30) were separated at 5months of age into three groups: 1) sham-operated (Sham); 2) ovariectomized (Ovx); and 3) ovariectomized chronically-treated with estrogen (Ovx+E2). Contractile responses to KCl (60mM) and thromboxane A(2) were greater in aorta from SAMP8 mice compared with SAMR1 in all groups. Neither ovariectomy nor estrogen replacement modified the contractile responses from SAMR1 mice. Conversely, in Ovx SAMP8 the increased maximal contract…
Expression of vascular endothelial growth factor receptors in the endometrium of septate uterus.
2008
Objective To compare the messenger RNA (mRNA) expression of vascular endothelial growth factor (VEGF) receptors (KDR, Flt-1, and sflt) in the different endometrial locations of septate uterus and normal uterus. Design Prospective, observational study. Setting University teaching hospital. Patient(s) Twelve women with complete septate uterus undergoing hysteroscopic metroplasty and 12 women with normal uterus. Intervention(s) Endometrial tissue samples were obtained from the endometrium covering the septum and the endometrium lining the lateral wall of the uterus. Moreover, endometrial samples were obtained from patients with normal uterus. Main Outcome Measure(s) Differences in the mRNA exp…
Development of predictive retention-activity relationship models of tricyclic antidepressants by micellar liquid chromatography.
1999
The distribution of tricyclic antidepressants from plasma to brain, where these drugs exert their main clinical action, and other organs is related to transport events across the cell membranes of the different tissues. It could be expected that all the molecular features that condition the transport processes (mainly hydrophobicity and molar total charge) also control the pharmacokinetic and biochemical behavior. Micellar liquid chromatography (MLC) has been proposed to emulate in vitro the partitioning process in the biomembranes. The use of micellar solutions of Brij35 as mobile phases in reversed-phase liquid chromatography has proven to be valid to predict the biological activities of …
Minireview: Nicotinic Acetylcholine Receptors on Hippocampal Neurons: Distribution on the Neuronal Surface and Modulation of Receptor Activity
1997
The recent development of a technique that uses infrared microscopy for the visualization of well-defined areas on the surface of neurons, and a computerized system of micromanipulators led to the discovery that functional nicotinic acetylcholine receptors (nAChRs) are expressed at higher density on the dendrites than on the soma of rat hippocampal neurons. The finding that the expression of alpha-bungarotoxin-sensitive, alpha 7-bearing, nAChRs and dihydro-beta-erythroidine-sensitive, alpha 4 beta 2 nAChRs tends to increase along the dendritic length suggests that these receptors may be highly involved in the integration of synaptic functions in hippocampal neurons. The present report also …
Unconventional ligands and modulators of nicotinic receptors
2002
Evidence gathered from epidemiologic and behavioral studies have indicated that neuronal nicotinic receptors (nAChRs) are intimately involved in the pathogenesis of a number of neurologic disorders, including Alzheimer's disease, Parkinson's disease, and schizophrenia. In the mammalian brain, neuronal nAChRs, in addition to mediating fast synaptic transmission, modulate fast synaptic transmission mediated by the major excitatory and inhibitory neurotransmitters glutamate and GABA, respectively. Of major interest, however, is the fact that the activity of the different subtypes of neuronal nAChR is also subject to modulation by substances of endogenous origin such as choline, the tryptophan …
Inhibition of FcεRI-mediated Activation of Rat Basophilic Leukemia Cells by Clostridium difficile Toxin B (Monoglucosyltransferase)
1996
Abstract Treatment of rat basophilic leukemia (RBL) 2H3-hm1 cells with Clostridium difficile toxin B (2 ng/ml), which reportedly depolymerizes the actin cytoskeleton, blocked [3H]serotonin release induced by 2,4-dinitrophenyl-bovine serum albumin, carbachol, mastoparan, and reduced ionophore A23187-stimulated degranulation by about 55-60%. In lysates of RBL cells, toxin B 14C-glucosylated two major and one minor protein. By using two-dimensional gel electrophoresis and immunoblotting, RhoA and Cdc42 were identified as protein substrates of toxin B. In contrast to toxin B, Clostridium botulinum transferase C3 that selectively inactivates RhoA by ADP-ribosylation did not inhibit degranulation…
Endotoxaemia resulting from decreased serotonin tranporter (5-HTT) function: A reciprocal risk factor for depression and insulin resistance?
2015
International audience; Depression and diabetes are serious diseases with an increasing global prevalence. Intriguingly, recent meta-analyses have highlighted an asymmetrical relationship between the two conditions as depressed patients were found to display a higher risk of developing type 2 diabetes than those individuals suffering from diabetes are to become depressed. Based on recent findings, we favor a hypothesis where by decreased peripheral serotonin (5-HT) transporter (5-HTT) function is a reciprocal risk factor for the comorbidity of depression and diabetes, as it can trigger inflammatory pathogenetic mechanisms of both conditions. Higher intestinal levels of 5-HT and 5-HT3 recept…
The effects of metoclopramide on acetylcholine release and on smooth muscle response in the isolated guinea-pig ileum
1982
The effects of metoclopramide on smooth muscle contraction and on release of acetylcholine were studied in the guinea-pig myenteric plexus longitudinal muscle preparation. Acetylcholine was determined either as endogenous acetylcholine, or as labelled transmitter from strips preloaded with 3H-choline. Metoclopramide caused an increase in resting tension of longitudinal muscle as well as an increase in resting output of either endogenous or labelled acetylcholine. Tetrodotoxin abolished the metoclopramide-evoked increase in transmitter release. The increase in smooth muscle tension was clearly related to the increase in resting output. The effects of metoclopramide on both longitudinal muscl…
Antidepressants are functional antagonists at the serotonin type 3 (5-HT3) receptor
2003
Antidepressants are commonly supposed to enhance serotonergic and/or noradrenergic neurotransmission by inhibition of neurotransmitter reuptake through binding to the respective neurotransmitter transporters or through inhibition of the monoamine oxidase. Using the concentration-clamp technique and measurements of intracellular Ca2+, we demonstrate that different classes of antidepressants act as functional antagonists at the human 5-HT3A receptor stably expressed in HEK 293 cells and at endogenous 5-HT3 receptors of rat hippocampal neurons and N1E-115 neuroblastoma cells. The tricyclic antidepressants desipramine, imipramine, and trimipramine, the serotonin reuptake inhibitor fluoxetine, t…