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  • Nitric oxide  (3)
  • Serotonin  (3)
  • wide crosses  (3)
  • 1
    Digitale Medien
    Digitale Medien
    p-Chlorophenylalanine, a serotonin synthesis inhibitor, reduces the response of glial fibrillary acidic protein induced by trauma to the spinal cord (1993)
    Springer
    Acta neuropathologica 86 (1993), S. 422-427 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Spinal cord trauma ; Glial fibrillary acidic protein ; Serotonin ; p-Chlorophenylalanine ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The possibility that serotonin may influence the early response of astrocytes around a spinal cord trauma was investigated in a rat model by making a unilateral incision into the right dorsal horn of the T10-11 segments. One group of rats received a serotonin synthesis inhibitor, p-chlorophenylalanine (p-CPA) before injury in doses which cause a depletion of serotonin in the cord. Another group of traumatised rats did not receive p-CPA. All animals were allowed to survive for 5 h. Samples for immunohistochemistry were taken from the T9, T10-11 and T12 segments of the cord. Paraffin sections were immunostained for glial fibrillary acidic protein (GFAP) using monoclonal antibodies and avidin-biotin complex technique. Trauma to the cord resulted in a marked increase of GFAP immunoreactivity in all the investigated segments, particularly in the ipsilateral side. Pretreatment with p-CPA markedly reduced the GFAP response. This drug did not by itself influence the GFAP immunoreactivity of the cord of untraumatised rats. Our results show that trauma to the spinal cord induces a rapid enhancement of GFAP immunoreactivity in the cord which is present even far away from the primary lesion. This response can be prevented by pretreatment with the serotonin synthesis inhibitor, p-CPA. The results indicate that serotonin influences the increase of GFAP immunoreactivity following spinal cord injury either directly or indirectly, for instance by its microvascular reactions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00228575
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  • 2
    Digitale Medien
    Digitale Medien
    Effects of p-chlorophenylalanine on microvascular permeability changes in spinal cord trauma (1990)
    Springer
    Acta neuropathologica 79 (1990), S. 595-603 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Trauma ; Spinal cord injury ; Microvascular permeability ; Serotonin ; p-Chlorophenylalanine (p-CPA)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The possibility that serotonin can take part in the initiation of the increased microvascular permeability occurring in a spinal cord trauma was investigated in a rat model with 131I-sodium and lanthanum as tracers. We influenced the serotonin content in the tissue pharmacologically by treating animals with a serotonin synthesis inhibitor, p-chlorophenylalanine (p-CPA), before the production of the injury and compared the results with injured, untreated controls. A small incision was made in the dorsal horn of the lower thoracic cord. It caused a progressive extravasation of 131I-sodium in the damaged segment, measured after 1,2 and 5 h. Rostral and caudal segments also showed a significant but lower accumulation of 131I-sodium. Lanthanum added to the fixative was used as an ionic tracer detectable by electron microscopy. The endothelial cells of microvessels removed from the perifocal region after 5 h showed a marked increase in the number of lanthanum-filled vesicles. Many endothelial cells had a diffuse penetration of the tracer into the cytoplasm and the basement membrane. However, the tight junctions usually remained closed to lanthanum. Pretreatment with p-CPA markedly reduced the extravasation of 131I-sodium measured at 5 h in the traumatized cord. At the cellular level, the endothelial vesicles filled with lanthanum approached the condition of uninjured animals. The diffuse infiltration of lanthanum into endothelial cells and its spread into the basement membrane of the vascular wall were usually absent. Our results indicate that serotonin plays a role in the initiation of the increased microvascular permeability which occurs in spinal cord injuries.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00294236
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  • 3
    Digitale Medien
    Digitale Medien
    Edema formation and cellular alterations following spinal cord injury in the rat and their modification with p-chlorophenylalanine (1990)
    Springer
    Acta neuropathologica 79 (1990), S. 604-610 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Trauma ; Spinal cord injury ; Edema ; Serotonin ; p-CPA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The possibility that serotonin can modify the early pathological sequences occurring in spinal cord trauma was investigated in a rat model. To that end we took advantage of the possibility of influencing serotonin pharmacologically by treating animals with a serotonin synthesis inhibitor, p-chlorophenylalanine (p-CPA) before the production of the injury and compared the results with injured, untreated controls. A unilateral incision was made into the dorsal horn of the lower thoracic cord (about 2.5 mm deep, 4.5 mm long) and the trauma. The injured region from untreated animals showed macroscopically at that time a pronounced swelling and the water content had increased by 3.5% as compared to intact controls. The segments rostral and caudal to the lesion also exhibited a profound increase in water content. Light microscopy revealed a significant expansion of the spinal cord as compared to controls. The swelling was most pronounced in the gray matter on the injured side. Electron microscopy showed distorted neurons, swollen astrocytes and extracellular edema in the gray matter in and around the primary lesion. There was also a sponginess in the surrounding white matter with disruption of myelin, collapsed axons and widened periaxonal spaces. Pretreatment of the rats with p-CPA significantly reduced the swelling of the injured spinal cord and there was no visible expansion. The ipsilateral edema in the central gray matter was considerable less pronounced as compared to that in untreated animals. The increase in water content was less than 1% in these animals. The neuronal and glial cell changes were also markedly reduced in the drugtreated rats. The disruption of myelin and the vacuolation of the gray matter were much less severe. Our results show that p-CPA can markedly modify the edema and the cellular changes occurring in the traumatic spinal injury and indicate that serotonin is somehow involved in the production of the early, and thus important, pathological events.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00294237
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  • 4
    Digitale Medien
    Digitale Medien
    Nitric oxide in the pathophysiology of hyperthermic brain injury. Influence of a new anti-oxidant compound H-290/51 (1998)
    Springer
    Amino acids 14 (1998), S. 95-103 
    Details
    ISSN: 1438-2199
    Schlagwort(e): Heat stress ; Nitric oxide ; Cell injury ; Antioxidant ; H-290/51Blood-brain barrier ; Brain edema
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The possibility that nitric oxide (NO) is involved in the pathophysiology of brain injury caused by heat stress (HS) was examined using neuronal nitric oxide synthase (NOS) immunohistochemistry in a rat model. In addition, to find out a role of oxidative stress in NOS upregulation and cell injury, the effect of a new antioxidant compound H-290/51 (Astra Hässle, Mälndal, Sweden) was examined in this model. Subjection of conscious young rats to 4 h HS in a biological oxygen demand (BOD) incubator at 38°C resulted in a marked upregulation of NOS in many brain regions compared to control rats kept at room temperature (21 ± 1°C. This NOS immunoreactivity was found mainly in distorted neurons located in the edematous regions not normally showing NOS activity. Breakdown of the blood-brain barrier (BBB) permeability, increase in brain water content and marked neuronal, glial and myelin reaction were common findings in several brain regions exhibiting upregulation of NOS activity. Pretreatment with H-290/51 significantly attenuated the upregulation of NOS in rats subjected to HS. In these animals breakdown of the BBB permeability, edema and cell changes were considerably reduced. Our results suggest that hyperthermic brain injury is associated with a marked upregulation of NOS activity in the CNS and this upregulation of NOS and concomitant cell injury can be reduced by prior treatment with an antioxidant compound H 290/51. These observations indicate that oxidative stress seems to be an important endogenous signals for NOS upregulation and cell reaction in hyperthermic brain injury.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01345249
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  • 5
    Digitale Medien
    Digitale Medien
    Spinal cord evoked potentials and edema in the pathophysiology of rat spinal cord injury (1998)
    Springer
    Amino acids 14 (1998), S. 131-139 
    Details
    ISSN: 1438-2199
    Schlagwort(e): Nitric oxide ; Spinal cord evoked potentials ; Edema ; Cell changes ; p-CPA ; Diazepam ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The possibility that nitric oxide is somehow involved in the early bioelectrical disturbances following spinal cord injury in relation to the later pathophysiology of the spinal cord was examined in a rat model of spinal cord trauma. A focal trauma to the rat spinal cord was produced by an incision of the right dorsal horn of the T 10–11 segments under urethane anaesthesia. The spinal cord evoked potentials (SCEP) were recorded using epidural electrodes placed over the T9 and T12 segments of the cord following supramaximal stimulation of the right tibial and sural nerves in the hind leg. Trauma to the spinal cord significantly attenuated the SCEP amplitude (about 60%) immediately after injury which persisted up to 1h. However, a significant increase in SCEP latency was seen at the end of 5h after trauma. These spinal cord segments exhibited profound upregulation of neuronal nitric oxide synthase (NOS) immunoreactivity, and the development of edema and cell injury. Pretreatment with a serotonin synthesis inhibitor drug p-chlorophenylalanine (p-CPA) or an anxiolytic drug diazepam significantly attenuated the decrease in SCEP amplitude, upregulation of NOS, edema and cell injury. On the other hand, no significant reduction in SCEP amplitude, NOS immunolabelling, edema or cell changes were seen after injury in rats pretreated with L-NAME. These observations suggest that nitric oxide is somehow involved in the early disturbances of SCEP and contribute to the later pathophysiology of spinal cord injury.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01345253
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  • 6
    Digitale Medien
    Digitale Medien
    Brain derived neurotrophic factor and insulin like growth factor-1 attenuate upregulation of nitric oxide synthase and cell injury following trauma to the spinal cord (1998)
    Springer
    Amino acids 14 (1998), S. 121-129 
    Details
    ISSN: 1438-2199
    Schlagwort(e): Brain derived neurotrophic factor ; Insulin like growth factor-1 ; Nitric oxide ; Spinal cord injury ; Edema ; Cell injury ; Blood-spinal cord barrier ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The possibility that brain derived neurotrophic factor (BDNF) and insulin like growth factor-1 (IGF) induced neuroprotectivn is influenced by mechanisms involving nitric oxide was examined in a rat model of focal spinal cord injury. BDNF or IGF-I (0.1 μg/10 [1 in phosphate buffer saline) was applied topically 30 min before injury on the exposed spinal cord followed by repeated doses of growth factors immediately before and 30 min after injury. Thereafter application of BDNF or IGF was carried out at every 1 h interval until sacrifice. Five hours after injury, the tissue pieces from the T9 segment were processed for nNOS immunostaining, edema and cell injury. Untreated injured rats showed a profound upregulation of nNOS which was most pronounced in the nerve cells of the ipsilateral side. A marked increase in the blood-spinal cord barrier (BSCB) permeability to125I-albumin, water content and cell injury in these perifocal segments was also found. Pretreatment with BDNF and IGF significantly reduced the upregulation of nNOS in the spinal cord. This effect of the growth factors was most pronounced in the contralateral side. Rats treated with these neurotrophic factors showed much less signs of BSCB damage, edema and cell injury. These results suggest that BDNF and IGF pretreatment is neuroprotective in spinal cord injury and that these neurotrophic factors have the capacity to down regulate nNOS expression following trauma to the spinal cord. Our data provide new experimental evidences which suggest that BDNF and IGF may exert their potential neuroprotective effects probably via regulation of NOS activity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01345252
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  • 7
    Digitale Medien
    Digitale Medien
    Crossability and embryo rescue enhancement in wide crosses between wheat and three Agropyron species (1990)
    Springer
    Euphytica 49 (1990), S. 209-214 
    Details
    ISSN: 1573-5060
    Schlagwort(e): Triticum aestivum ; wheat ; Agropyron spp. ; embryo rescue ; wide crosses ; crossability
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Soft winter wheat lines were crossed with Agropyron intermedium, A. elongatum and A. trichophorum using pollen from single plants of Agropyron spp. to pollinate wheat spikes. Not only species but also individual plants within varieties of Agropyron species differed in percent seed set with a wheat genotype. In two arrays of crosses between two phenotypically different plants of A. elongatum and nine wheat lines, one Agropyron plant gave higher seed set (overall=27.1%) than the other (overall=3.7%). The differences were significant in seven of the nine cross combinations. Results are consistent with the hypothesis that these two plants differ in their crossability as pollen parents with wheat, and suggest the possibility of occurrence of crossability genes in wheatgrasses. The success rate of hybrid embryo rescue was higher (87.5%) with cold treatment (4°C) than without cold treatment (75.0%) of excised embryos on culture media. Results underscore the significance of genotype of the alien species for crossing with low crossable wheats, and of the physical factors for improving embryo rescue in wide crosses.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00036290
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  • 8
    Digitale Medien
    Digitale Medien
    Inflorescence culture of wheat-Agropyron hybrids: Callus induction, plant regeneration, and potential in overcoming sterility barriers (1984)
    Springer
    Plant cell, tissue and organ culture 3 (1984), S. 247-255 
    Details
    ISSN: 1573-5044
    Schlagwort(e): Triticum aestivum ; wide crosses ; tissue culture ; somaclonal variation ; Agropyron
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Segments of young inflorescences of Triticum aestivum cv. Chinese Spring (CS), its F1 hybrids with Agropyron trachycaulum and A. scirpeum and backcross derivatives with A. yezoense, A. intermedium and A. junceum, and of a A. yezoense x T. aestivum cv. Wichita hybrid were cultured. Different parts of young spikelets of A. trachycaulum x CS F1 and A. yezoense x Wichita F1 's were also cultured. Percent callus induction was lower in wheat than in the wheat-Agropyron hybrids or backcross derivatives. Percent callus induction from different organs in both hybrids was in the descending order of whole spikelet, spikelet without glumes, rachis, and glumes. No plants could be regenerated from calli of wheat and backcross derivatives except those of CS x A. intermedium combination. Callus induction in hybrids varied from 54 to 84% and plant regeneration from 14 to 31%. The regenerants required no vernalization. Variants including one with top-dense spikes and another with elongated spikelets were recovered. Out of eight A. trachycaulm x CS hybrid regenerants, one had anthers and stigma as opposed to neutral flowers of the original hybrid.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00040344
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  • 9
    Digitale Medien
    Digitale Medien
    Anther culture and chromosome reduction in wheat × Thinopyrum wide crosses (1999)
    Springer
    Plant cell, tissue and organ culture 57 (1999), S. 215-218 
    Details
    ISSN: 1573-5044
    Schlagwort(e): anther culture ; intergeneric crosses ; interspecific crosses ; wide crosses
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract There is little information on the anther culture response and cytogenetic nature of pollen-derived calli and regenerants of wide crosses in wheat. The anther culture response of three Thinopyrum species (wheatgrasses), their hybrids and backcrosses with wheat, and the chromosome composition of calli and regenerants were studied to determine the feasibility of efficient chromosome elimination and production of alien addition lines from wide crosses by anther culture in comparison with conventional backcrossing and selfing. Wide hybrids between wheat and wheatgrasses had up to a 2% callus induction response. Pollen sterility of wide hybrids and recalcitrance of wheatgrass parents may largely be responsible for their low response, in addition to culture stage, media and environmental factors. Anther culturability improved in backcrosses as the proportion of wheatgrass chromosomes decreased and fertility increased. Overall the wheat × Th. trichophorum cross had the best response; that is up to 37% callus induction from some BC2 plants. A large variation was found in chromosome numbers in callus roots examined in the BC2 generation. Mixoploidy was frequent. Data indicated that the chromosome numbers in the pollen-derived organs/plants can be reduced to produce alien addition lines.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1006348107665
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