Search results for "Autoradiography"
showing 10 items of 60 documents
Relation between autoradiographically measured blood flow and ATP concentrations obtained from imaging bioluminescence in tumors following hypertherm…
1993
The effects of moderate local hyperthermia (43.3 degrees C/30 min) on regional blood flow and regional ATP distribution in the amelanotic hamster melanoma A-Mel-3 were investigated by high-resolution techniques. Blood flow and ATP concentrations were measured simultaneously in treated and untreated tumors and in adjacent tissues by means of (14C)-Iodoantipyrine autoradiography and quantitative imaging bioluminescence in consecutive tissue sections at 3, 12 and 24 hr following treatment. Digital image processing and the use of a special algorithm allowed the regional interrelationship of the 2 parameters to be quantified. Measurements revealed a great heterogeneity of blood flow and ATP betw…
Mapping of the high molecular weight kininogen binding site of prekallikrein. Evidence for a discontinuous epitope formed by distinct segments of the…
1993
Prekallikrein, a glycoprotein involved in contact phase activation, circulates in plasma in the form of a binary complex with high molecular weight kininogen (H-kininogen). The binding to H-kininogen is mediated by the prekallikrein heavy chain consisting of four repetitive domains, A1-A4. To define more precisely the region(s) involved in kininogen binding, we have employed an affinity cross-linking strategy with a synthetic peptide of 31 residues which mimics the prekallikrein binding site of H-kininogen. Cross-linking of the radiolabeled peptide to (pre)kallikrein revealed a binding segment in the NH2-terminal portion of the prekallikrein heavy chain; another binding segment was located …
Multiple actions of fenamates and other nonsteroidal anti-inflammatory drugs on GABAA receptors
2019
The nonsteroidal anti-inflammatory drug (NSAID) niflumic acid, a fenamate in structure, has many molecular targets, one of them being specific subtypes of the main inhibitory ligand-gated anion channel, the GABA(A) receptor. Here, we report on the effects of other fenamates and other classes of NSAIDs on brain picrotoxinin-sensitive GABA A receptors, using an autoradiographic assay with [S-35]TBPS as a ligand on mouse brain sections. We found that the other fenamates studied (flufenamic acid, meclofenamic acid, mefenamic acid and tolfenamic acid) affected the autoradiographic signal at low micromolar concentrations in a facilitatory-like allosteric fashion, i.e., without having affinity to …
Cellular expression of connexins in the rat brain: neuronal localization, effects of kainate-induced seizures and expression in apoptotic neuronal ce…
2003
The identification of connexins (Cxs) expressed in neuronal cells represents a crucial step for understanding the direct communication between neurons and between neuron and glia. In the present work, using a double-labelling method combining in situ hybridization for Cx mRNAs with immunohistochemical detection for neuronal markers, we provide evidence that, among cerebral connexins (Cx26, Cx32, Cx36, Cx37, Cx40, Cx43, Cx45 and Cx47), only Cx45 and Cx36 mRNAs are localized in neuronal cells in both developing and adult rat brain. In order to establish whether connexin expression is influenced in vivo by abnormal neuronal activity, we examined the short-term effects of kainate-induced seizur…
Preliminary in vivo and ex vivo evaluation of the 5-HT2A imaging probe [18F]MH.MZ
2009
Abstract Introduction The 5-HT 2A receptor is one of the most interesting targets within the serotonergic system because it is involved in a number of important physiological processes and diseases. Methods [ 18 F]MH.MZ, a 5-HT 2A antagonistic receptor ligand, is labeled by 18 F-fluoroalkylation of the corresponding desmethyl analogue MDL 105725 with 2-[ 18 F]fluoroethyltosylate ([ 18 F]FETos). In vitro binding experiments were performed to test selectivity toward a broad spectrum of neuroreceptors by radioligand binding assays. Moreover, first micro-positron emission tomography (μPET) experiments, ex vivo organ biodistribution, blood cell and protein binding and brain metabolism studies of…
18F-labeling and evaluation of novel MDL 100907 derivatives as potential 5-HT2A antagonists for molecular imaging.
2009
Abstract Introduction The serotonergic system, especially the 5-HT2A receptor, is involved in various diseases and conditions. It is a very interesting target for medicinal applications. Methods Two novel 5-HT2A tracers, namely, [ 18 F]DD-1 and the enantiomeric pure ( R )-[ 18 F]MH.MZ, were radiolabeled by 18 F-fluoroalkylation of the corresponding desmethyl analogue. In vitro binding autoradiography on rat brain slices was performed to test the affinity and selectivity of these tracers. Moreover, first μPET experiments of ( R )-[ 18 F]MH.MZ were carried out in Sprague-Dawley rats. Results [ 18 F]DD-1 ( K i =3.23 nM) and ( R )-[ 18 F]MH.MZ ( K i =0.72 nM) were 18 F-fluoroalkylated by the se…
Erucic acid metabolism in rat liver. A combined biochemical and radioautographical study.
1992
Metabolism of erucic acid was studied in rat liver in comparison with oleic acid in relation with diet lipids. Rats were fed for 3 or 60 days a balanced diet containing 30% of the calories of either rapeseed oil rich in erucic acid or sunflower seed oil rich in linoleic acid. They were intravenously injected with tritiated erucic or oleic acid. After 1 or 15 min, the radioactivity recovered in liver lipids was 9 to 26% whatever the diet or the acid injected. One minute after injection of erucic acid a high part of radioactivity was recovered in the free fatty acid fraction and as untransformed erucic acid. After 15 min the major part of radioactivity was recovered in the triacylglycerol fra…
Changes in the expression of neurotransmitter receptors in Parkin and DJ-1 knockout mice – A quantitative multireceptor study
2015
Parkinson's disease (PD) is a well-characterized neurological disorder with regard to its neuropathological and symptomatic appearance. At the genetic level, mutations of particular genes, e.g. Parkin and DJ-1, were found in human hereditary PD with early onset. Neurotransmitter receptors constitute decisive elements in neural signal transduction. Furthermore, since they are often altered in neurological and psychiatric diseases, receptors have been successful targets for pharmacological agents. However, the consequences of PD-associated gene mutations on the expression of transmitter receptors are largely unknown. Therefore, we studied the expression of 16 different receptor binding sites …
Proliferative response of cells of the dentogingival junction to mechanical stimulation
2001
SUMMARY The aim of this research was to study the proliferative response of junctional epithelium (JE) and gingival connective tissue (GCT) to mechanical stimulation in vivo with regard to the potential occurrence of apical migration of JE and loss of GCT attachment during orthodontic tooth movement. Elastic bands were inserted between the maxillary first and second molars of male rats aged 8 weeks, which were pulse-labelled with 3 H-thymidine and subsequently killed in groups, together with labelled control animals (a total of 98 rats) after periods of 1‐168 hours. Autoradiographs were prepared from plastic mesiodistal sections, and parameters of cell proliferation for JE and GCT of the pa…
Time-course of GDNF and its receptor expression after brain injury in the rat
2008
Abstract The aim of the present work was to perform, by in situ hybridization, a time-course analysis of the glial cell line-derived neurotrophic factor (GDNF) and its receptor mRNA expression in two models of brain injury in the rat: (a) excitotoxic lesion by ibotenic acid injection in the hippocampal formation; (b) mechanical lesion by needle insertion through the cerebral cortex including the white matter of the corpus callosum. The time-course analysis, ranging from 6 h to 8 days, showed that the GDNF and its receptor (RET, GFRα-1 and GFRα-2) mRNA expressions were differentially up-regulated in both models of lesion. This in vivo regulation of the GDNF and its receptor mRNA expression i…