Intrinsic vasoactive intestinal polypeptide (VIP)-containing neurons in the baroreceptor nucleus of the solitary tract in rat

Vasoactive intestinal polypeptide (VIP)-immunoreactive cell bodies, dendrites and nerve terminals in the nucleus of the solitary tract have been identified with electron microscopic immunocytochemistry in rats. The relatively high concentration of VIP in this nucleus, which corresponds to the primary baroreceptor center, was depleted only insignificantly by uni- or bilateral transection of the solitary tract, which eliminates peripheral neuronal (via glossopharyngeal and vagal nerves) input to the nucleus. Both immunocytochemical and biochemical data suggest that the majority of VIP in the nucleus of the solitary tract is present in intrinsic neurons.     

1,2-Bis-benzothiophenyliden-ethane aus 1-Thiochromanonen

1,2-Bis(benzothiophenylidene)ethanes from 1-Thiochromanones The method described in the literature for the synthesis of 3,3′-bithiochromones 4a and 4b from the 3-bromothiochromanones 1a and 1b ²⁾ does not lead to the expected products, but results in the formation of the bis(benzothiophenylidene)ethanes 9a and 9b .     

Dimere Cannabinoide mit Ethanbrücke

Dimeric Cannabinoids with an Ethane Bridge The dimeric ethane-bridged coumarin derivatives 5a, 10a, 12a, 14a, 18a and 19a result from a Pechmann-Duisberg reaction of the tetrahydroxy(diphenyl)ethanes 3 and 17a with β-ketocarboxylic esters. These can be converted into the dimeric cannabinoids 8, 10d, 12b, 14c, 18d and 19d through a Grignard reaction.     

Aza-, Di- und Triazaxanthone aus Azachromonen

Aza-, Di- and Triazaxanthones from Azachromones The acyl(methylthio)azachromones 7a and 7b , which are obtained from the pyridyl-substituted 1,3-dicarbonyl compounds 5a and 5b , react with amines, hydrazine compounds, amidine or CH-acidic compounds to yield the azaxanthones 8a, 8b, 9a and 9b, 11a and 11b , or 13 and 14 .     

2-Amino-3-hydroxy-1-thiochromones

2-Amino-3-hydroxy-l-thiochromones The 2-amino-3-hydroxy(resp.-3-alkoxy)-l-thiochromones 9a or 17a-17d can be obtained by reduction of the 2-nitro or 2-phenylazo derivatives 8a or 11 or by reaction of the 2-bromo derivative 16c with secondary amines. Compounds 9a and 16a are starting materials for the synthesis of the fused thiochromones 12a-12e , 13 and 18 . In screening tests with mice 8a and 17d affected the central nervous system.     

Characterization of LRF-like immunoreactivity in the frog sympathetic ganglia: Non-identity with LRF decapeptide

A substance resembling luteinizing hormone-releasing hormone (LRF) has previously been demonstrated in preganglionic elements of the bullfrog, where it is released upon nerve stimulation and produces a slow excitatory post-synaptic potential (slow EPSP) of the principal ganglion cells (1). This LRF-like immunoreactive substance (IR-LRF) has been characterized immunologically employing several antisera specific for LRF and by high-pressure liquid chromatography (HPLC). The IR-LRF of the sympathetic ganglia is recognized by LRF antiserum R-42 but not by several other LRF antisera (IJ-29, 185 and WP-1) in a radioimmunoassay (RIA). Reverse-phase HPLC allows the separation of sympathetic ganglion (SG) IR-LRF from LRF decapeptide. In contrast, frog brain contains IR-LRF which is identical to LRF decapeptide on the basis of its immunological characteristics and co-chromatography with LRF decapeptide using reverse-phase HPLC. The IR-LRF of frog SG may be structurally related to LRF decapeptide.     

Xanthone aus Chromon-Derivaten

Xanthones from Chromone Derivatives The 3-acyl-2-(methylthio)chromones 2a - 2c and the 6-acetyl-7-(methylthio)furochromone 10 react with the CH-acidic compounds 5a-5f, 11 and potassium tert.-butylate to yield the 3-acylchromones 4a - 4d and 9 , the xanthones 1 und 6a - 6d and the furoxanthones 13a-13c and 20 . With ammonium acetate, 4b and 4c gave the benzopyranopyridinones (azaxanthones) 8a - 8b .     

Multiple populations of neuropeptide-containing cells in cultures of the bovine adrenal medulla

Cell populations containing vasoactive intestinal polypeptide (VIP), enkephalins, and catecholamines were identified in bovine adrenal medullary cultures by immunofluorescence and radioimmunoassay. Addition of forskolin to the culture medium increased the cellular levels of both VIP and the enkephalins. These changes resulted from an increase in the number of VIP-positive cells and an increase in cellular enkephalin content.     

The effect of methylazoxymethanol acetate (MAM) on the developing rat retina

The morphological effects of methylazoxymethanol acetate (MAM) on the prenatal and postnatal rat retina were studied using light and electron microscopy. MAM was injected into pregnant rats once on days 9(E9) to 20(E20) of gestation, or into newborn pups once on days 1(PE1) through 9(PE9) after birth. Some of the retinas were examined 3–4 weeks after birth and others at 5 months. A second group of rats was injected with MAM on day PE1 and killed at 24-h intervals to day PE9. The retina from adult animals treated with MAM between days E17 and PE5 (except day E20) showed pathological damage. The retinas from adult animals treated with MAM before E17 and after PE5 appeared normal. Retinas from animals examined daily after injection of MAM had, within 2 days of the treatment, pyknotic cells and necrosis in the neuroblastic layer. By 5 days after treatment no necrotic material was visible. At 3 days after treatment, dark cells, believed to be aberrant developing photoreceptor cells, were adjacent to the pigment epithelium. These cells appeared to be the focal point for formation of rosettes which occurred on subsequent days.The developing rat retina is sensitive to MAM during gestation and the early postnatal period. Before E17 when most of the cells were still in the proliferating pool, the retina may have been able to repair the MAM-induced injury and develop normal cytoarchitecture. Between E17 and PE6 when more and more cells became postmitotic the retina was not able to compensate and rosettes were formed. Finally, after PE6 when most cells were postmitotic and less were killed by MAM, the retina again appeared not to be affected.