摘要:

AbstractThe effect of isoprenaline, carbachol, substance P (SP) and neurokinin A (NKA) on peroxidase and total protein secretion was studied in the developing postnatal submandibular glands of the rat usingin vitromethods. Submandibular glands of 1, 5, 12 and 30 day‐old‐rats were stimulated by 10−5M isoprenaline and carbachol, and 10−6M SP and NKA. The stimulatory effects of these compounds were compared to the basic release of peroxidase and total amount of protein from submandibular gland fragments in incubation solution with no added transmitter substances. Indirect immunohistochemical methods were used to study these developing glands from SP‐ and NKA‐immunoreactive (IR) nerve fibers. The distributions of SP‐IR and NKA‐IR nerve fibers closely resembled each other, being most abundantly spread around the developing acini and ducts. The number of these fibers was high on the 1st, 5th and 12th days, but was decreased on the 30th day. On peroxidase release, isoprenaline was the most effective, causing a maximal response of 47 times the basic release on the first postnatal day, after which it gradually decreased. The effects of carbachol, SP and NKA on peroxidase release were clearly weaker and, unlike isoprenaline, their strongest response was on the 5th postnatal day (carbachol, 4.3; SP 5.2; NKA, 4.5). The total protein secretion effect patterns of the studied substances resembled each other more, showing their strongest response on the 5th day (isoprenaline, 5.0; carbachol, 4.5; SP, 4.2; NKA, 3.4) and decreasing thereafter.In general, both the stimulatory pattern of SP and NKA, and the appearance and distribution of SP‐IR and NKA‐IR nerve fibers during the early postnatal period of development closely resemble those of parasympathetic nerves and their transmitters. Furthermore, it is concluded that the abundancy of SP‐IR and NKA‐IR nerves in the developing submandibular gland is accompanied by the increased sensitivity of the secretory elements to these tachykinins, indicating that they play a role in the maturation of the glandular secretory functions.

ISSN:0736-5748    

DOI:10.1016/0736-5748(94)90039-6

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractNeuronal ceroid lipofuscinosis (NCL) is a type of lysosomal storage disease resulting in the progressive deterioration of neuronal function. Little is known about the genetics, pathophysiology and biochemical basis of this disease. This is, in part, due to the complexity of the central nervous system and the lack of anin vitromodel. In this report, we describe the conditions to establish neuronal cells in primary culture from the brains of newborn English setters with NCL, a canine model for this disease. Over 80% of the neuronal cells from normal dog brain establish well‐developed interconnecting networks of long neurites. On the contrary, approximately 50% of the neurons cultured from NCL dog brains do not assemble neurites. Of those NCL neurons with processes, the neurites are routinely shorter and fewer in number than those seen in normal cultures. In addition, the characteristic inclusion bodies, pathological markers for this diseasein vivo, are prevalent in the soma of cultured neuronal cells isolated from NCL dog brain. A time‐dependent maturation of the inclusion bodies suggests a progression of the disease state in culture. The reduced ability of the NCL neurons to establish neurites prompted us to examine the effects of growth factors on neurite assembly. Our data show that insulin‐like growth factor I, epidermal growth factor and platelet‐derived growth factor are capable of stimulating neurite outgrowth of NCL neurons.We report the establishment and morphological characterization of neuronal cultures from normal and NCL dog brains. The abnormal morphology of cultured NCL neurons can, in part, be alleviated by supplementing the medium with growth factors. The results suggest that this cellular model of NCL will be useful to study the molecular and physiological mechanisms of NCL disease, as well as to test potential therapeutic agents and candidate genes.

ISSN:0736-5748    

DOI:10.1016/0736-5748(94)90040-X

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractLectin‐binding histochemistry was used to investigate the distribution and density of defined carbohydrate sequences on the cell surface glycoproteins of the olfactory receptors of rat during development. The olfactory and vomeronasal receptors showed a positive labelling after biotinylatedLycopersicum esculentumlectin binding on embryonic day 16 (E16), while horseradish peroxidase‐labelledGlycine max,Bandeiraea simplicifolia(BS A‐I) and its B4isomer BSA‐I‐B4agglutinins started to label from day 18 (E18). From this stage onward there was a progressive increase in the intensity and number of lectin‐binding olfactory receptors. The first lectin‐labelled bundles of axons penetrating the olfactory bulb were observed on E20; from E21 it was possible to identify the first labelled glomeruli that, on the first day (P1) of postnatal life, showed a feature very similar to that of the adult. The lectin staining patterns indicate that during development there are differences in the kind and distribution of saccharidic moieties on the surface of rat olfactory neurons. The possible role of carbohydrate‐containing glycoproteins in the reception and transduction of the odours and in the modulation of the cell‐cell interactions in the olfactory system is discussed.

ISSN:0736-5748    

DOI:10.1016/0736-5748(94)90041-8

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractEcto‐ and endo‐Ca‐adenosine‐triphosphatase (ATPase) activity was identified as electrondense lead or cerium phosphate precipitate in the rat cortical synaptosomes by transmission electron microscopy and enzyme histochemistry. The formation of the deposit was dependent on the presence of ATP (the substrate), Ca (activator) and levamisole, quercetin or ouabain (inhibitors of different phosphatases and ATPases). Reaction products were found at the external surface of the presynaptic membrane, both surfaces of the postsynaptic membrane, in the synaptic cleft and in the free mitochondrial membranes. In the presence of ATP and the three inhibitors together, the quantity of the precipitate decreased markedly, but we still found some deposit on the external surface of the presynaptic membrane (this activity is probably due to the so‐called ecto‐ATPase) and on the internal surface of the postsynaptic one (endo‐ATPase). The distinction between ecto‐ and endo‐ATPases in biochemical fractions solely upon biochemical differential measurements must be interpreted with caution.

ISSN:0736-5748    

DOI:10.1016/0736-5748(94)90042-6

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractWeaver (wv/wv) mutant mice are characterized by extensive granule cell degeneration and can therefore be used as a model for brain degeneration that does not involve blood‐brain barrier damage. The ontogeny of the neural cell adhesion molecule (NCAM) and the neuronal antigen D3 protein were investigated in cerebellum and forebrain of weaver mutant mice up to post‐natal day 60. In the forebrain the concentration of both proteins was virtually unchanged. In cerebellum, in contrast, the concentration of D3 decreased markedly whereas that of NCAM remained unchanged. Similar findings were obtained at post‐natal day 30 in the cerebellum of other neurologic mutants, namely the staggerer (sg/sg) and reeler (rl/rl). At this age the concentration of a synaptic vesicle marker, synaptophysin. was severely decreased in the cerebellum of all three mutants. The concentration of neuron‐specific enolase was less affected, whereas the concentrations of the glial markers glutamine synthetase and glial fibrillary acidic protein were both increased. The NCAM/D3 concentration ratio, which probably reflects the ongoing rate of synaptic remodelling, was increased during the whole ontogeny of weaver mutant mice as compared with heterozygous controls. At post‐natal day 30, the ratio was increased by 180% in weaver, by 170% in staggerer and by 60% in reeler cerebellum. These findings lend further support to the usefulness of the NCAM/D3 ratio as a marker of neural plasticity and synaptic remodelling in both animals and man.

ISSN:0736-5748    

DOI:10.1016/0736-5748(94)90043-4

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractIt was the purpose of the present study to evaluate glutamate‐stimulated phosphatidylinositol metabolism in primary mixed astrocyte/neuron and neuron‐enriched cortical cultures through different stages of developmentin vitro. Glutamate (0–200 μM) stimulated inositol phosphate accumulation in a concentration‐dependent fashion at 6, 13 and 20 daysin vitro. Pure astrocyte cultures exhibited glutamate‐stimulated phosphatidylinositol hydrolysis only at high concentrations (100–400 μM), indicating that these cells contribute little to the overall inositol phosphate accumulation measured in mixed neuronal cultures treated with low glutamate concentrations. Comparison of mixed neuronal cultures with and without antimitotic treatment revealed that increasing astrocyte number suppressed glutamate‐stimulated responses, presumably via glutamate uptake. In contrast to previous reports, glutamate‐stimulated inositol phosphate accumulation, when expressed as a function of cell number, increased with increasing daysin vitro.

ISSN:0736-5748    

DOI:10.1016/0736-5748(94)90044-2

出版商:Wiley    

年代:2003

数据来源: WILEY

ISSN:0736-5748    

DOI:10.1016/0736-5748(94)90045-0

出版商:Wiley    

年代:2003

数据来源: WILEY

ISSN:0736-5748    

DOI:10.1016/0736-5748(94)90046-9

出版商:Wiley    

年代:2003

数据来源: WILEY