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T V Ostroumova

Publications and source records attributed to T V Ostroumova.

13 recordsLinked to original sources
PubMed2000

[Effect of inhibitors of synthesis of dopamine and its antagonists on Hydra attenuata regeneration].

Obvious inhibition of the hydra regeneration with no subsequent morphological abnormalities, was shown to occur when using alpha-methylthyrosine and 3 Jthyrosine. alpha-Methyldopa induced a slight inhibition but a considerable morphological change: ectopic tentacles, projections, bipolar forms in the gastric fragment. The apical and basal fragments did not suffer. The role of neurotransmitters in the hydra morphogenesis is discussed.

Animals↗
PubMed1982

The action of low-intensity pulsed ultrasound on amphibian embryonic tissues.

Amphibian embryos at different stages of development, and ectomesodermal explants (small pieces of embryonic tissue extirpated from lateral parts of the embryos just after neurulation), have been irradiated with continuous and pulsed ultrasound at a frequency of 0.88 MHz, spatial and temporal average intensities being within the range 0.025-0.1 W cm2. Ultrasound pulse repetition frequencies were varied within 10-1000 Hz, duty factor being constant and equal to 0.5. Destruction of embryonic tissue as an immediate effect, and interruption or distortion of development as delayed (24 hr) effects, were registered. Significant damaging effects of non-cavitational and non-thermal origin and dependent on pulse repetition frequencies, were observed. Highly frequency-dependent resonance-type effects were obtained for irradiated explants. The maximum effect on Rana temporaria explants was obtained at pulse repetition frequencies of 10-20 Hz and on Xenopus laevis explants at 110-130 Hz.

Animals↗
PubMed1979

[Regional differences in the sensitivity of the metabolism of coelenterate larvae to external influences].

The regional differences in the sensitivity of protein synthesis and free radical processes to temperature, trypsin, urea and LiCl were studied in Obelia flexuosa by means of autoradiography. The regional differences were also determined with respect to the rate of incorporation and excretion of a labelled aminoacid under the normal conditions. The metabolic reactions of larvae can be divided in primary (the first 30 min following the effect) and subsequent adaptive ones. The primary reactions are characterized by the greater sensitivity of the anterior larval regions to all factors under study. The subsequent reactions are characterized by synchronous and unidirectional metabolic starts in both the anterior and posterior larval regions, the starts being bigger in the anterior regions. The restoration of the normal ratios of metabolic activities of the opposite larval regions does not always correlate with the restoration of the normal absolute level of metabolism. The adaptive reactions are better expressed for protein synthesis, rather than for free radical processes. The anterior larval region has the greatest metabolic non-stability by a series of indices.

Adaptation, Physiological↗
PubMed1978

[Distribution of the intensity of free radical reactions at different stages of bud growth and in adult hydra].

The distribution of free radical reactions was studied by means of grafted copolymerization of 14C-acrylamide monomer in the ectoderm of growing bud and adult Hydra. Several states of regionalization were established in the process of bud growth: absence of local differences, presence of local differences and presence of the peak of free radical reactions in the hypostome region, characteristic of adult Hydra. The initiation of budding is not accompanied by the activation of free radical reactions in this region. No direct relationship between the metabolic regionalization and morphological rearrangements was found.

Acrylamides↗
PubMed1977

[Dynamics of the regional metabolic differences in the early development of the sea urchin].

The regional differences in Strongylocentrotus intermedius from the stage of 32 blastomeres till the middlelate gastrula stage were studied by the vital and supravital staining (intensity of oxidative-reductive processes), the incorporation of 3H-leucine (intensity of protein synthesis) and 14C-acrilamide (intensity of free radical processes). Two periods of rapid switches of metabolic intensity correlated within the same embryo were established. The beginning of the first period coincides with the onset of blastula epithelization and that of the second one with the onset of gastrulation. The metabolic "patterns" are multivariant up to the second switch although, in the most cases, the metabolic activity of the equatorial area is the lowest. From the onset of gastrulation the metabolic patterns become uniform: the vegetative area dominates by the intensity of precursors' incorporation and by the sensitivity of its respiratory systems to the oxygen deficiency. The relationships between the metabolic and morphological rearrangements are discussed.

Acrylamides↗
PubMed1975

[Regionalization of protein synthesis in hydra].

An autoradiographic assay of protein biosynthesis (by 3H-leucine incorporation) in buds and adults Hydra attenuata has shown that in the process of bud growth the following states of protein synthesis regionalization can be distinguished: absence of local differences, state of local differences, and state of hypostomal peak characteristic of the adult Hydra. The protein synthesis regionalization and the morphological segmentation are independent in the process of bud growth.

Animals↗
PubMedDate not supplied

The effects of dopamine synthesis inhibitors and dopamine antagonists on regeneration in the hydra Hydra attenuata.

The effects of catecholamine synthesis inhibitors (alpha-methyltyrosine, 3-iodotyrosine, and alpha-methyl-DOPA) and dopamine receptor blockers (haloperidol and spiperone) on the regeneration of apical, gastral, and basal fragments of the hydra Hydra attenuata were studied. These experiments showed that alpha-methyltyrosine and 3-iodotyrosine significantly inhibited regeneration but did not produce morphological anomalies. Alpha-Methyl-DOPA produce less inhibition of regeneration, but induced ectopic tentacles and outgrowths in gastral regenerates. Haloperidol and spiperone had no significant effect on the rate of regeneration but induced significant numbers of morphogenetic anomalies in gastral regenerates. Apical and basal regenerates, which retained their natural organizers (the head and base respectively) never yielded morphogenetic anomalies in the presence of either dopamine receptor blockers or dopamine synthesis inhibitors. The possible role of neurotransmitters. particularly dopamine, in morphogenesis in hydras is discussed.

Animals↗