The role of neurohumors in early embryogenesis

Development ◽  
1968 ◽  
Vol 20 (1) ◽  
pp. 119-128
Author(s):  
G. A. Buznikov ◽  
I. V. Chudakova ◽  
L. V. Berdysheva ◽  
N. M. Vyazmina
Keyword(s):  
Molecular Weight ◽  
Xenopus Laevis ◽  
Sea Urchin ◽  
Early Embryogenesis ◽  
Low Molecular Weight ◽  
Insect Eggs ◽  
Insect Embryos ◽  
Related Compounds ◽  
Xenopus Laevis Embryos

In a previous paper (Buznikov, Chudakova & Zvezdina, 1964) it has been reported that serotonin (5-hydroxytryptamine, 5-HT) may be involved in early embryogenesis in various groups of animals. This conclusion was confirmed by Baker's recent publication (Baker, 1965) concerning 5-HT synthesis in Xenopus laevis embryos. Some other low molecular weight substances, neurohumors or related compounds, are known to be synthesized in fertilized eggs as well. Acetylcholine (ACh) synthesis in sea-urchin eggs and embryos was demonstrated by Numanoi (1953, 1955, 1959, 1961). It seems possible that ACh can be synthesized in fertilized insect eggs as well (Morley & Schachter, 1963; Schachter, 1964). The synthesis of another neurohumor, dopamine (DA), in early insect embryos seems to be indisputable (Furneaux & McFarlane, 1965). However, in most cases changes in the level of neurohumors with age have not been studied. In the present paper data concerning the change of concentration with age of ACh and catecholamines (adrenaline (A) and noradrenaline (NA)) in early sea-urchin embryos will be presented.

The role of substrate identity on microbial processing of low molecular weight organics in soil solution

2020 ◽  
Author(s):  
K. Cyle ◽  
Annaleise Klein ◽  
Ludmilla Aristilde ◽  
Carmen Martinez
Keyword(s):  
Molecular Weight ◽  
Soil Solution ◽  
Low Molecular Weight

The role of neurohumours in early embryogenesis

Development ◽  
1970 ◽  
Vol 23 (3) ◽  
pp. 549-569
Author(s):  
G. A. Buznikov ◽  
A. N. Kost ◽  
N. F. Kucherova ◽  
A. L. Mndzhoyan ◽  
N. N. Suvorov ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Functional Activity ◽  
Early Onset ◽  
Active Sites ◽  
Physiological Effect ◽  
Early Embryogenesis ◽  
Dopamine Synthesis ◽  
Direct Involvement ◽  
Misgurnus Fossilis

In previous papers (Buznikov, Chudakova & Zvezdina, 1964; Buznikov, Chudakova, Berdysheva & Vyazmina, 1968) we reported that fertilized eggs of the sea-urchin Strongylocentrotus dröbachiensis synthesized a number of neurohumours, such as serotonin (5-hydroxytryptamine, 5-HT), acetylcholine (ACh), adrenalin (A), noradrenalin (NA) and dopamine. Synthesis of 5-HT was also demonstrated in the fertilized eggs of the loach Misgurnus fossilis and some marine Invertebrata. In experiments with sea-urchin embryos we were able to trace regular changes in the level of 5-HT, ACh, A and NA, related to the first cleavage divisions. This early onset of neurohumour synthesis, as well as regular changes in their level, suggests their direct involvement in the regulation of the first cleavage divisions. The functional activity of neurohumours (M) in adult organisms is realized through their reaction with the active sites of corresponding receptors (R) according to the following equation:The magnitude of the physiological effect under certain conditions is linearly proportional to the number of complexes MR formed (Turpayev, 1962; Ariëns, 1964).

Polyamine metabolism and function

1982 ◽  
Vol 243 (5) ◽  
pp. C212-C221 ◽  
Author(s):  
A. E. Pegg ◽  
P. P. McCann
Keyword(s):  
Molecular Weight ◽  
Tissue Growth ◽  
Polyamine Metabolism ◽  
Organic Cations ◽  
Low Molecular Weight ◽  
Polyamine Biosynthesis ◽  
Polyamine Content ◽  
And Function ◽  
Specific Inhibitors

Polyamines are ubiquitous organic cations of low molecular weight. The content of these amines is closely regulated by the cell according to the state of growth. The reactions responsible for the biosynthesis and interconversion of the polyamines and their precursor putrescine are described and the means by which polyamine content can be varied in response to exogenous stimuli are discussed. The role of polyamines in the cell cycle, cell division, tissue growth, and differentiation is considered. Recent studies using highly specific inhibitors of polyamine biosynthesis such as alpha-difluoromethylornithine to prevent accumulation of polyamines have indicated that the synthesis of polyamines is intimately associated with these processes. Such inhibitors have great potential for investigation of the cellular role of polyamines.

Role of the Primary Specificity Subsite on the Interaction between Serine Proteinases and Low Molecular Weight Substrates and Inhibitors

1987 ◽  
pp. 101-115 ◽  
Author(s):  
Enea Menegatti ◽  
Mario Guarneri ◽  
Martino Bolognesi ◽  
Paolo Ascenzi ◽  
Gino Amiconi
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
Serine Proteinases ◽  
Primary Specificity

scholarly journals Imaging patterns of calcium transients during neural induction in Xenopus laevis embryos

2000 ◽  
Vol 113 (19) ◽  
pp. 3519-3529 ◽  
Author(s):  
C. Leclerc ◽  
S.E. Webb ◽  
C. Daguzan ◽  
M. Moreau ◽  
A.L. Miller
Keyword(s):  
Xenopus Laevis ◽  
Calcium Signalling ◽  
Neural Induction ◽  
Calcium Transients ◽  
Free Calcium ◽  
Treated Animal ◽  
Cell Stage ◽  
Subsequent Formation ◽  
Xenopus Laevis Embryos

Through the injection of f-aequorin (a calcium-sensitive bioluminescent reporter) into the dorsal micromeres of 8-cell stage Xenopus laevis embryos, and the use of a Photon Imaging Microscope, distinct patterns of calcium signalling were visualised during the gastrulation period. We present results to show that localised domains of elevated calcium were observed exclusively in the anterior dorsal part of the ectoderm, and that these transients increased in number and amplitude between stages 9 to 11, just prior to the onset of neural induction. During this time, however, no increase in cytosolic free calcium was observed in the ventral ectoderm, mesoderm or endoderm. The origin and role of these dorsal calcium-signalling patterns were also investigated. Calcium transients require the presence of functional L-type voltage-sensitive calcium channels. Inhibition of channel activation from stages 8 to 14 with the specific antagonist R(+)BayK 8644 led to a complete inhibition of the calcium transients during gastrulation and resulted in severe defects in the subsequent formation of the anterior nervous system. BayK treatment also led to a reduction in the expression of Zic3 and geminin in whole embryos, and of NCAM in noggin-treated animal caps. The possible role of calcium transients in regulating developmental gene expression is discussed.

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