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151.
Stimulation of inositol phospholipid breakdown in pig brain miniprisms by carbachol and monoamines: effect of K+ 总被引:1,自引:0,他引:1
1. The effects of carbachol, monoamines and K+ upon the rate of inositol phospholipid breakdown in pig brain miniprisms have been investigated. 2. In the striatum, carbachol (EC50 approx. 1 microM) and noradrenaline (EC50 approx. 25 microM) stimulated inositol phospholipid breakdown, whereas 5-hydroxytryptamine (1-1000 microM) was without effect. 3. The rate of inositol phospholipid breakdown was increased by raising the assay [K+] to greater than or equal to 40 mM. In the hippocampus and hypothalamus, a synergistic effect between K+ and carbachol was noted, whereas in the striatum, the effects were additive. 4. In striatal and hippocampal miniprisms, dopamine also increased inositol phospholipid breakdown, albeit only at high (greater than or equal to 1 mM) concentrations. Dopamine (1 mM) reduced the stimulation produced by noradrenaline (1 mM), suggesting that the effect of dopamine is due to a weak noradrenergic action of this catecholamine. 相似文献
152.
Robert A. Mueller Thomas J. McCown Ricky D. Hunt Cecilia Lundberg George R. Breese 《Cellular and molecular neurobiology》1990,10(3):327-336
1. | Rats which survived hypoglycemia by insulin, hypoxia by 10% O2, or ischemia by carotid ligation and hypotension to 40 mm Hg, evidenced no changes in cerebrospinal fluid (CSF) uridine. Animals which died soon after the above interventions or as a result of KCl-induced cardiac arrest had elevated CSF uridine concentrations. |
2. | Injection of whole blood or the soluble contents of lysed blood cells into the lateral ventricle of rats reduced CSF uridine to less than one-half normal at 24 hrs but values returned to normal 3 days later. Changes in hypoxanthine resembled those of uridine, but were less dramatic, whereas xanthine concentrations were largely unaltered. Intraventricular injection of plasma or saline did not alter CSF uridine. |
3. | It seems most likely that low CSF uridine concentrations previously reported in head injury patients may be secondary to the effects of blood cell contents in the cerebrospinal fluid, rather than responses to altered metabolism in neurons or glia cells. |
153.
The 76 kD cell-adhesion factor from crayfish haemocytes promotes encapsulation in vitro 总被引:2,自引:0,他引:2
Summary Semigranular cells from the crayfish, Pacifastacus leniusculus, were separated by Percoll gradient centrifugation and were used to study the encapsulation of foreign particles. The semigranular cells were found strongly to encapsulate glass beads coated with haemocyte lysate in which the prophenoloxidase-activating system had been activated with laminarin or with a low concentration of calcium ions. The granular cells only weakly encapsulated these particles. The encapsulationpromoting factor was purified from haemocyte lysates and found to be a 76 kD protein which was recognized by an antiserum to the previously described 76 kD cell-adhesion factor. After the last step in purification (Con A-Sepharose chromatography), the flowthrough consisted of several proteins, which had some, but less, encapsulation-promoting activity and contained a 30 kD band that was also recognized by the antiserum to the 76 kD cell-adhesion factor. If the haemocyte lysate prepared in low [Ca2+] was incubated with a -1,3-glucan prior to purification, no 76 kD protein could be isolated but only a 30 kD protein. The 30 kD protein thus seems to be a degradation product of the 76 kD cell-adhesion factor. We conclude that the 76 kD protein which is released from degranulating haemocytes, and to a lesser extent its 30 kD fragment, can promote encapsulation. Phenoloxidase did not have any encapsulation-promoting activity. 相似文献
154.
J. S. Lacroix A. Änggård T. Hökfelt M. M. T. O'Hare J. Fahrenkrug J. M. Lundberg 《Cell and tissue research》1990,259(1):119-128
Summary The occurrence of neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP) and peptide histidine isoleucine (PHI) in the sympathetic and parasympathetic innervation of the nasal mucosa was studied in various species including man. A dense network of NPY-immunoreactive (IR) fibres was present around arteries and arterioles in the nasal mucosa of all species studied. NPY was also located in nerves around seromucous glands in pig and guinea-pig, but not in rat, cat and man. The NPY-IR glandular innervation corresponded to about 20% of the NPY content of the nasal mucosa as revealed by remaining NPY content determined by radioimmunoassay after sympathectomy. These periglandular NPY-positive fibres had a distribution similar to the VIP-IR and PHI-IR nerves but not to the noradrenergic markers tyrosine hydroxylase (TH) or dopamine--hydroxylase (DBH). The NPY nerves around glands and some perivascular fibres were not influenced by sympathectomy and probably originated in the sphenopalatine ganglion where NPY-IR and VIP-IR ganglion cells were present. The venous sinusoids were innervated by NPY-positive fibres in all species except the cat. Dense NPY and DBH-positive innervation was seen around thick-walled vessels in the pig nasal mucosa; the latter may represent arterio-venous shunts. Double-labelling experiments using TH and DBH, and surgical sympathectomy revealed that the majority of NPY-IR fibres around blood vessels were probably noradrenergic. The NPY-positive perivascular nerves that remained after sympathectomy in the pig nasal mucosa also contained VIP/PHI-IR. The major nasal blood vessels, i.e. sphenopalatine artery and vein, were also densely innervated by NPY-IR fibres of sympathetic origin. Perivascular VIP-IR fibres were present around small arteries, arterioles, venous sinusoids and arterio-venous shunt vessels of the nasal mucosa whereas major nasal vessels received only single VIP-positive nerves. The trigeminal ganglion of the species studied contained only single TH-IR or VIP-IR but no NPY-positive ganglion cells. It is concluded that NPY in the nasal mucosa is mainly present in perivascular nerves of sympathetic origin. In some species, such as pig, glandular and perivascular parasympathetic nerves, probably of VIP/PHI nature, also contain NPY. 相似文献
155.
Jens Ewers Doris Freier-Schröder Hans-Joachim Knackmuss 《Archives of microbiology》1990,154(4):410-413
Two isoprene (2-methyl-1,3-butadiene) utilizing bacteria, Alcaligenes denitrificans ssp. xylosoxidans JE 75 and Rhodococcus erythropolis JE 77, were identified as highly efficient cooxidizers of TCE, cis- and transdichloroethene, 1,1-dichloroethene and vinylchloride. Isoprene grown cells eliminate chloride from TCE in stoichiometric amounts and tolerate high concentrations of TCE. 相似文献
156.
Aurelio Serrano Patricia Giménez Siegfried Scherer Peter Böger 《Archives of microbiology》1990,153(6):614-618
The in situ location of the electron carrier protein cytochrome C
553 (cyt c
553) has been investigated in both vegetative cells and heterocysts of the cyanobacterium Anabaena variabilis ATCC 29413 using the antibody-gold technique, carried out as a post-ernbedding immunoelectron microscopy procedure. When using a rabbit polyclonal anti-cyt c
553 specific antiserum an intense labelling, associated mainly with the cell periphery (cytoplasmic membrane and periplasmic area), was seen in both heterocysts and vegetative cells. The selective release of most of the cellular cyt c
553 during a Tris-EDTA treatment confirms a periplasmic localization of this protein in A. variabilis. The results indicate that most of cyt c
553 is located in the periplasmic space. The roles ascribed to this protein in both respiration and photosynthesis in cyanobacteria are discussed.Abbreviations Cyt c
553
cytochrome c
553
- PBS
phosphate buffered saline (20 mM sodium phosphate, 0.9% NaCl, pH 7.4)
- PMSF
phenylmethylsulfonyl fluoride
Recipient of a Research Fellowship of the Alexander von Humboldt Foundation (Bonn, FRG) for a leave to the University of Konstanz. 相似文献
157.
158.
Cecilia Gotor Eloísa Pajuelo Luís C. Romero Antonio J. Márquez José M. Vega 《Archives of microbiology》1990,153(3):230-234
Polyclonal antiserum specific for ferredoxin-nitrite reductase (EC 1.7.7.1) from the green alga Chlamydomonas reinhardii recognized the nitrite reductase from other green algae, but did not cross-react with the corresponding enzyme from different cyanobacteria or higher plant leaves. An analogous situation was also found for ferredoxin-glutamate synthase (EC 1.4.7.1), using its specific antiserum. Besides, the antibodies raised against C. reinhardii ferredoxin-glutamate synthase were able to inactivate the ferredoxin-dependent activity of nitrite reductase from green algae.These results suggest that there exist similar domains in ferredoxin-nitrite reductases and ferredoxin-glutamate synthases from green algae. In addition, both types of enzymes share common antigenic determinants, probably located at the ferredoxin-binding domain. In spite of their physicochemical resemblances, no apparent antigenic correlation exists between the corresponding enzymes from green algae and those from higher plant leaves or cyanobacteria.Abbreviations Fd
ferredoxin
- GOGAT
glutamate synthase
- MV+
reduced methyl viologen (radical cation)
- NiR
nitrite reductase
- PMSF
phenylmethylsulphonyl fluoride
- SDS
sodium dodecyl sulfate 相似文献
159.
Eberhard Bock Hans-Peter Koops Uwe C. Möller Michael Rudert 《Archives of microbiology》1990,153(2):105-110
A total of 17 facultatively lithoautotrophic strains of Nitrobacter were investigated. They all were found to be related on the species level by DNA hybridizations. The G+C content of DNA ranged between 58.9 and 59.9 mol %. The isolates originated from divers environments. The cells were 0.5–0.8×1.2–2.0 m in size and motile by one polar to subpolar flagellum. Cell-division normally occurred by budding. Polar caps of intracytoplasmic membranes as well as carboxysomes were present. The cells tended to excrete extracellular polymers forming aggregates or biofilms. Heterotrophic growth was slower than mixotrophic but often faster than litoautotrophic growth. In the presence of nitrite and organic substances the organisms often showed diphasic growth. First nitrite and then the organic material was oxidized. In the absence of oxygen growth was possible by dissimilatory nitrate reduction. Nitrite, nitric and nitrous oxide as well as ammonia were formed. Depending on growth conditions the generation times varied from 12 to 140 h. The new Nitrobacter spec. may be one of the most abundant nitrite-oxidizing bacteria in soils, fresh waters and natural as well as artificial stones. For this organism the name Nitrobacter vulgaris is proposed.The type strain is filed with the culture collection of the Institut für Allgemeine Botanik, Universität Hamburg, FRG. 相似文献
160.
G. Schöner 《Biological cybernetics》1990,63(4):257-270
The concepts of pattern dynamics and their adaptation through behavioral information, developed in the context of rhythmic movement coordination, are generalized to describe discrete movements of single components and the coordination of multiple components in discrete movement. In a first step we consider only one spatial component and study the temporal order inherent in discrete movement in terms of stable, reproducible space-time relationships. The coordination of discrete movement is captured in terms of relative timing. Using an exactly solvable nonlinear oscillator as a mathematical model, we show how the timing properties of discrete movement can be described by these pattern dynamics and discuss the relation of the pattern variables to observable end-effector movement. By coupling several such component dynamics in a fashion analogous to models of rhythmic movement coordination we capture the coordination of discrete movements of two components. We find the tendency to synchronize the component movements as the discrete analogon of in-phase locking and study its breakdown when the components become too different in their dynamic properties. The concept of temporal stability leads to the prediction that remote compensatory responses occur such as the restore synchronization when one component is perturbed. This prediction can be used to test the theory. We find that the discrete analogon to antiphase locking in rhythmic movement is a tendency to move sequentially, a finding that can also be subjected to empirical test. 相似文献