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1.
2.
Tatsuro Koike 《Journal of neurochemistry》1987,49(6):1784-1789
The binding and internalization of 125I-nerve growth factor (NGF) by PC12 pheochromocytoma cells was studied as a function of extracellular potassium concentration. Both surface-bound and internalized fractions of 125I-NGF associated with the cells under depolarizing conditions (50 mM K+) increased to 144 +/- 28% (average +/- SEM, six different cell preparations) and to 176 +/- 12% (n = 6), respectively, of those observed at 6.0 mM K+. Scatchard-type analysis of the data indicates increased sites for the binding and internalization of iodinated NGF by the cells. Similar enhancement was observed for cells treated with NGF as well. This voltage-dependent phenomenon was reversible, and also observed in the presence of veratridine. Moreover, withdrawal of extracellular Ca2+ abolished high K+-induced modulation of 125I-NGF binding and internalization, indicating that this effect may be mediated by Ca2+. 相似文献
3.
Magdalena Torres M. France Bader Dominique Aunis M. Teresa Miras-Portugal 《Journal of neurochemistry》1987,48(1):233-235
Chromaffin cells both recently isolated or in culture present a high-affinity adenosine transporter with a Km value of 1 microM. When cells were exposed to nerve growth factor (NGF; 10 ng/ml), the adenosine transporter affinity decreased to 3 microM. This value was maintained from 3 days after plating to the end of the culture period. A change in the transport capacity was observed, with a significant increase (approximately 200-260%) in NGF-cultured cells throughout the period studied. 相似文献
4.
5.
Neuromedin U-immunoreactivity in the nervous system of the small intestine of the pig and its coexistence with substance P and CGRP 总被引:2,自引:0,他引:2
Jean-Pierre Timmermans Prof. Dietrich W. Scheuermann Werner Stach Dirk Adriaensen Marie H. A. De Groodt-Lasseel Julia M. Polak 《Cell and tissue research》1989,258(2):331-337
Summary In the small intestine of the pig, neuromedin U (NMU)-immunoreactivity was mainly confined to the nerve plexus of the inner submucosal and mucosal regions. After colchicine treatment, a high number of immunoreactive nerve cell bodies was observed in the plexus submucosus internus (Meissner), whereas only a low number was found in the plexus submucosus externus (Schabadasch). The plexus myentericus as well as the aganglionic nerve meshworks in the circular and longitudinal smooth muscle layers almost completely lacked NMU-immunoreactivity. Double-labeling experiments demonstrated the occurrence of distinct NMU-containing neuron populations in the plexus submucosus internus: (1) relatively large type-II neurons revealing immunoreactivity for NMU and calcitonin gene-related peptide (CGRP) and/or substance P (SP); (2) a group of small NMU- and SP-immunoreactive neurons; (3) a relatively low number of small neurons displaying immunoreactivity for NMU but not for SP. Based on its distributional pattern, it is concluded that NMU plays an important role in the regulation and control of mucosal functions. 相似文献
6.
Elizabeth Knyihár-Csillik Pasko Rakic Prof. Dr. Bert Csillik 《Cell and tissue research》1989,258(3):515-525
Summary Transection of the sciatic nerve in Rhesus monkeys and the consequent transganglionic degenerative atrophy (TDA) of central terminals of primary afferents result in transneuronal degeneration of substantia gelatinosa (SG) cells. Severe degeneration is characterized by an increased electron density of the nucleus and by conspicuous shrinkage of the cytoplasm, mitochondrial swelling, dilation of cisterns of the rough-surfaced endoplasmic reticulum, accumulation of free ribosomes and an electron-dense material in the cytoplasm. In the mild form, dilation of cisternal elements of the endoplasmic reticulum, swollen mitochondria and accumulation of free ribosomes takes place. About 10% of SG cells in segment L5 undergo the severe form whereas the rest shows signs of the mild form. Cytoplasmic alterations that occur during transneuronal degeneration seem to start at the level of subsurface cisterns. Dendrites and axons of transneuronally degenerating SG cells also show a conspicuous electron density. By analyzing the synaptic relationships of such darkened dendrites, connections in the upper dorsal horn can be deciphered. Modular units of the primary nociceptive analyzer that evaluate noxious and innocuous inputs on the basis of thin versus thick (AC/A) afferent activity and subjecting them to descending control appear to be recruited from structurally dispersed elements of synaptic glomeruli. These are arranged alongside dendritic processes of large antenna cells which relay impulses to projection cells of the spinothalamic tract. 相似文献
7.
Paul L. Wood Tadimeti S. Rao Smriti Iyengar Thomas Lanthorn Joseph Monahan Alex Cordi Eric Sun Michael Vazquez Nancy Gray Patricia Contreras 《Neurochemical research》1990,15(2):217-230
Conclusions Current neurochemical studies of the NMDA receptor macromolecular complex are yielding new insights into the interactions of the subunits of this complex and the associated potential clinical benefits of selective modulation of these subnits. Such studies offer the great potential for a new generation of pharmacotherapies for a wide range of CNS disorders, including stroke, a condition for which there is currently no effective pharmacological treatment. However, it is essential to understand that the first generation products in this area may not be optimal pharmacotherapies, such that haracterization of possible receptor subtypes and understanding the molecular biology of the component proteins of the receptor complex will be crucial in the design of the optimal pharmacological modulators of the NMDA receptor complex.Special issue dedicated to Dr. Erminio Costa 相似文献
8.
Katsuhiko Yanagisawa Hideaki Ishigro Kiyotoshi Kaneko Tadashi Miyatake 《Neurochemical research》1990,15(5):483-486
The vacuolar degeneration of central myelin was produced in Sprague-Dawley rats by oral administration of triethyl tin. The wet weight of brain stems which seems to reflect the degree of accumulation of water increased during the administration of the toxin, whereas the activity of 2, 3-cyclic nucleotide 3-phosphodiesterase altered less remarkably. When TET was withdrawn from the drinking water, the rats showed a dramatic clinical improvement along with reduction in wet weight of brain stems. Treatment with acetazolamide following TET inhibited the clinical improvement and reduction in wet weight of brain stems. The present results indicates that central myelin has plasticity in recovering from the vacuolar degeneration by removing the accumulated fluid and carbonic anhydrase is possibly involved in the dehydration, of myelin in such a recovery phase. 相似文献
9.
Dr. Emiko Matsumoto Kazushige Hirosawa Kiyoshi Takagawa Yoshiki Hotta 《Cell and tissue research》1988,252(2):293-300
Summary A Drosophila visual mutant rdgA has photoreceptive cells which degenerate gradually after eclosion. Fine structure of the retinular cells of rdgA
KS60
and rdgA
K014
was studied during early stages of degeneration to determine the initial morphological defects. The retinular cells of these two alleles showed the following structural abnormality within 1 day after eclosion: (1) rhabdomeres were small and irregular in shape; (2) cisternae of the rough endoplasmic reticulum were more numerous than those in normal retinular cells; (3) submicrovillar cisternae were absent; and (4) lysosomes were fewer than normal. Three-dimensional reconstruction of serial sections of the ommatidia showed that the degeneration of mutant rhabdomeres proceeds more rapidly in regions remote from the nuclei. These results suggest that the process of turnover of rhabdomeric microvilli is abnormal in rdgA. We also confirmed an increase of lysosomes and destruction of cellular organelles, as reported by previous investigators at more advanced stages of degeneration. 相似文献
10.
The effect of optic nerve transsection on proteolytic degradation of axonally transported proteins in the superior colliculus of the rabbit was studied. Proteolysis of labeled proteins was determined in vitro in small pieces of the superior colliculus. Within 2 hours after sectioning the optic nerve there was a decreased degradation of slowly transported labeled proteins in the nerve terminals in the superior colliculus.Special Issue dedicated to Prof. Holger Hydén. 相似文献