Search results for "Amidines"
showing 10 items of 34 documents
Distribution and targets of the relaxin-3 innervation of the septal area in the rat.
2012
Neural tracing studies have revealed that the rat medial and lateral septum are targeted by ascending projections from the nucleus incertus, a population of tegmental GABA neurons. These neurons express the relaxin-family peptide, relaxin-3, and pharmacological modulation of relaxin-3 receptors in medial septum alters hippocampal theta rhythm and spatial memory. In an effort to better understand the basis of these interactions, we have characterized the distribution of relaxin-3 fibers/terminals in relation to different septal neuron populations identified using established protein markers. Dense relaxin-3 fiber plexuses were observed in regions of medial septum containing hippocampal-proje…
Distribution of origin of nitric oxide synthase-immunoreactive nerve fibers in the rat epididymis.
1996
Abstract Distribution of neuronal nitric oxide synthase-immunoreactive (nNOS-IR) nerve fibers and somata in the rat epididymis and major pelvic ganglia was studied by immunohistochemical methods. In the epididymis, the supply of nNOS-IR fibers was highest in the cauda and became progressively fewer toward the caput. In the cauda and corpus, nNOS-IR fibers were distributed throughout the subepithelial tissues and around the epithelium. The pattern of distribution of vasoactive intestinal polypeptide (VIP)- and tyrosine hydroxylase (TH)-immunoreactive fibers in the epididymis was similar but the latter was generally more numerous in a given region as compared to that of nNOS-IR fibers. A popu…
Calcitonin gene-related peptide-like immunoreactivity in spinal cord and superior cervical ganglion of the djungarian hamster (Phodopus sungorus)
1993
The indirect immunofluorescent method was employed to investigate the distribution of calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) in the spinal cord and superior cervical ganglion of the Djungarian hamster Phodopus sungorus. In cross-sections of the spinal cord, immunoreactive fibres and terminals were found in laminae 1 and 2 in high density, in the dorsolateral (Lissauer's) tract, in ventral and lateral horns, and in the area surrounding the central canal. A few CGRP-LI perikarya were seen in the ventral but not the dorsal horn. CGRP-LI was further observed in preganglionic sympathetic neurons which were labelled by retrograde axonal transport of fluoro-gold (FG) follo…
Neurochemistry of olivocochlear neurons in the hamster.
2009
The present study was conducted to characterize the superior olivary complex (SOC) of the lower brain stem in the pigmented Djungarian hamster Phodopus sungorus. Using Nissl-stained serial cryostat sections from fresh-frozen brains, we determined the borders of the SOC nuclei. We also identified olivocochlear (OC) neurons by retrograde neuronal tracing upon injection of Fluoro-Gold into the scala tympani. To evaluate the SOC as a putative source of neuronal nitric oxide synthase (nNOS), arginine-vasopressin (AVP), oxytocin (OT), vasoactive intestinal polypeptide (VIP), or pituitary adenylate cyclase-activating polypeptide (PACAP) that were all found in the cochlea, we conducted immunohistoc…
A nitrergic projection from the superior olivary complex to the inferior colliculus of the rat
2003
The present study was conducted to test whether the ascending auditory projection from the superior olivary complex (SOC) of the brainstem to the inferior colliculus (IC) may use nitric oxide (NO) as a neuroactive compound. We identified olivo-collicular projection neurons in subnuclei of the SOC by retrograde neuronal tracing with Fluoro-Gold (FG) injected into the central nucleus of the IC. Sections containing retrograde labelled neurons were subjected to immunohistochemical incubation in an antiserum directed against the enzyme responsible for NO production in nerve cells, neuronal NO synthase (nNOS). The analysis showed that FG-containing neurons as well as nNOS-immunoreactive neurons w…
Principal neurons projecting to the pineal gland in close association with small intensely fluorescent cells in the superior cervical ganglion of rats
1988
The localization in the superior cervical ganglia (SCG) of small, intensely fluorescent (SIF) cells and of principal nerve (PN) cells innervating the pineal gland was examined in adult male Sprague-Dawley rats. PN cells were demonstrated by means of the retrograde neuron-tracing method using the fluorescent tracer Fluoro-Gold (FG) injected into the pineal gland. SIF cells were visualized by the formaldehyde-induced fluorescence method. Twenty-nine percent of the FG-labeled PN cells were found closely associated with SIF cells. In the rostral half of the ganglion, 43% of the SIF cells were situated in juxtaposition to one or several labeled neurons. The possible influence of SIF cells on the…
Amidino substituted 2-aminophenols: biologically important building blocks for the amidino-functionalization of 2-substituted benzoxazoles
2021
Unlike the closely related and widely investigated amidino-substituted benzimidazoles and benzothiazoles with a range of demonstrated biological activities, the matching benzoxazole analogues still remain a largely understudied and not systematically evaluated class of compounds. To address this challenge, we utilized the Pinner reaction to convert isomeric cyano-substituted 2- aminophenols into their amidine derivatives, which were isolated as hydrochlorides and/or zwitterions, and whose structure was confirmed by single crystal X-ray diffraction. The key step during the Pinner synthesis of the crucial carboximidate intermediates was characterized through mechanistic DFT calculations, with…
Fluorescent substituted amidines of benzanthrone: synthesis, spectroscopy and quantum chemical calculations.
2012
Abstract Several new substituted amidine derivatives of benzanthrone were synthesized by a condensation reaction from 3-aminobenzo[de]anthracen-7-one and appropriate aromatic and aliphatic amides. The obtained derivatives have a bright yellow or orange fluorescence in organic solvents and in solid state. The novel benzanthrone derivatives were characterized by TLC analysis, 1H NMR, IR, MS, UV/vis, and fluorescence spectroscopy. The solvent effect on photophysical behaviors of these dyes was investigated, and the results showed that the Stoke’s shift increased, whereas quantum yield decreased with the growth of the solvent polarity. The structure of some dyes was confirmed by the X-ray singl…
Photoinduced molecular rearrangements. The photochemistry of 1,2,4-oxadiazoles in the presence of sulphur nucleophiles. Synthesis of 1,2,4-thiadiazol…
1997
Abstract The photochemistry of some 1,2,4-oxadiazoles in the presence of sulphur nucleophiles has been investigated. Irradiation of the 5-amino-3-phenyl- and 3,5-diphenyl-1,2,4-oxadiazole at γ = 254 nm in methanol in the presence of sodium hydrogen sulphide or thiols gave a photo-induced redox reaction at the ring ON bond, leading to the corresponding N -substituted benzamidines. By contrast, irradiation of the 5-amino-3-phenyl-1,2,4-oxadiazole in the presence of thioureas or thiocarbamates, essentially gave 3-phenyl-5-substituted 1,2,4-thiadiazoles, which presume an NS bond formation between the ring-photolytic species and the sulphur nucleophile. In turn, irradiation of the same 5-amino…
Preclinical Retinal Neurodegeneration in a Model of Multiple Sclerosis
2012
Neurodegeneration plays a major role in multiple sclerosis (MS), in which it is thought to be the main determinant of permanent disability. However, the relationship between the immune response and the onset of neurodegeneration is still a matter of debate. Moreover, recent findings in MS patients raised the question of whether primary neurodegenerative changes can occur in the retina independent of optic nerve inflammation. Using a rat model of MS that frequently leads to optic neuritis, we have investigated the interconnection between neurodegenerative and inflammatory changes in the retina and the optic nerves with special focus on preclinical disease stages. We report that, before manif…