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Biomedical subjects

I G Vladimirova

Publications and source records attributed to I G Vladimirova.

16 recordsLinked to original sources
PubMed1975

Growth and respiration of regenerating tissues of the axolotl tail.

Changes in the weight and oxygen consumption were studied during regeneration of the tail in adult axolotls and larvae. The curve of the increase in weight of the regenerating tail in both age groups is S-shaped. The intensity of respiration of the regenerating tail increases in adult axolotls and in larvae at the blastema stage; in adult axolotls there is also a second increase in the intensity of respiration of the regenerating tail during differentiation of the muscles. The relationship between weight and the rate of respiration was compared during regeneration of the tail in axolotl and the normal growth of the animals. Whereas growth of the animals was characterized by the relationship QO2 equals aPk with a constant value of k, during regeneration the various stages of this process have their own corresponding values of k.

Ambystoma↗
PubMedDate not supplied

[Evolutionary bioenergetic trap and progressive evolution of animals].

We propose a macroscopic pathway to increase energy metabolism during progressive evolution with reducing size of animal body. If standard metabolism significantly increases in the course of body size reduction through increased coefficient b from the allometric equation (1), two cases are possible: coefficient b remains constant (1) or returns to the normal value (2) at increasing body weight in a given animal group. In the first case, an animal group appears in an evolutionary trap considering possible increase in body size, since the standard metabolism at increasing weight becomes lower starting from a certain point as compared to other animals of the same type. In the second case, increasing body size elevates standard metabolism relative to other animals of the same type, which offers an evolutionary advantage to this group.

Animals↗
PubMedDate not supplied

[Dynamics of the intensity of respiration in early embryogenesis of amphibians].

We studied growth and respiration rate during early ontogenesis of the axolotl Ambystoma mexicanum, Bosca's newt Triturus waltlii, the green toad Bufo viridis, and the smooth clawed frog Xenopus laevis. The respiration rate in these amphibian species increases during embryonal and larval development, peaks after transition to active feeding, and decreases at later stages of ontogenesis. The patterns of dynamics of this energy metabolism index in tailed and tailless amphibians have some differences related to their specific development. The changes in respiration rate in the embryos and larvae are correlated with the concentrations of mitochondria.

Amphibians↗
PubMedDate not supplied

[Standard metabolism in Gastropoda].

The relationship between oxygen consumption and soft tissue weight in the Gastropoda class (according to the obtained and published data) is expressed by the equation with coefficients a = 0.71 and k = 0.78. Prosobranch and pulmonate snails have similar levels of oxygen consumption. Opisthobranch snails have higher oxygen consumption. No relationship has been revealed between the metabolic rate (coefficient a) and climatic zone of the gastropod habitat.

Adaptation, Physiological↗
PubMedDate not supplied

[Respiration rate and species-specific lifespan in fresh water bivalves of Margaritiferidae and Unionidae families].

We studied changes in the respiration rate in five species of freshwater bivalves as a function of animal age and size. The species-specific lifespan was calculated on the basis of the obtained data: Rubner's constant (Ru) and lifespan at standard temperature 20 degrees C (T20). The longest and shortest lifespan among the studied mollusks was specific for the pearl mussel Margaritifera margaritifera (Ru = 37 kJ and T20 = 36 years) and the freshwater mussel Anodonta anatina (Ru = 8 kJ and T20 = 8 years), respectively.

Animals↗
PubMedDate not supplied

[Energy metabolism and body mass ratio in bivalves mollusca (Mollusca: Bivalvia)].

On the basis of experimental and published data, the interspecific and intraspecific (ontogenetic) dependence of energy metabolism on body weight in bivalves was calculated. Changes in the parameters of intraspecific allometric dependence under the effect of environmental factors were analyzed. The rate of comparable standard metabolism (coefficient a at k = 0.76) was shown to vary in different taxonomic and zoogeographic groups of bivalves.

Adaptation, Physiological↗
PubMedDate not supplied

[The dependence of respiratory intensity on body mass in representative Caudata and Salientia].

Experimental data indicate dependence of the respiration rate on the body mass in both caudate and ecaudate amphibians. The regression line slopes are similar in the both groups, while the a factor value is 3 times lower in the caudates than it is in ecaudates. There certain sex differences in the respiration rate which have no clear biological interpretation.

Animals↗
PubMedDate not supplied

[Change in intensity of respiration in development of some invertebrates].

We studied the dynamic of respiration intensity during ontogenesis of flat worms (Dugesia tigrina), molluscs (Anodonta piscinalis and Viviparus viviparus, and insects (Leptinotarsa decemlineata). In planarians that reproduce vegetatively, the intensity of respiration increases just after fission and decreases at the subsequent phases of growth. In A. piscinalis, this index of metabolism increases during embryonic and early larval development and decreases at the later developmental stages. In V. viviparus, which develops in the female genital tract, the intensity of respiration remains unchanged during embryogenesis and decreases during late embryogenesis and subsequent phases of growth. In L. decemlineata, the intensity of respiration increases during embryonic and early larval development and then decreases to undergo cyclic changes times to molts. This index markedly decreases in the pupae, increases in the beginning of imaginal period, and then again decreases.

Animals↗
PubMedDate not supplied

[Specific growth rate and the rate of energy metabolism in the ontogenesis of axolotl, Ambystoma mexicanum (Amphibia: Ambystomatidae)].

Concordant changes in the rate of energy metabolism and specific growth rate of axolotls have been revealed. Several periods of ontogeny are distinguished, which differ in the ratio of energy metabolism to body weight and, therefore, are described by different allometric equations. It is suggested that the specific growth rate of an animal determines the type of dependence of energy metabolism on body weight.

Ambystoma mexicanum↗
PubMedDate not supplied

[Growth and oxygen consumption in embryonic and early postembryonic development of European pond turtle Emys orbicularis (Reptilia: Emydidae)].

Experiments on developing eggs of European pond turtle (Emys orbicularis) demonstrated S-shaped changes in the rate of oxygen consumption and body weight during embryonic development. The rate of oxygen consumption and weight progressively increased within 70 days after hatching. During embryogenesis, the rate of oxygen consumption decreased. After hatching, it increased but then decreased to a certain level, which remained constant to the end of the studied period. We observed unidirectional changes in oxygen consumption rate during embryonic period and this pattern was maintained after hatching as well. The coefficients of the allometric relationship between oxygen consumption and body weight were a = 0.33 and k = 0.52 during the embryonic period and a = 0.17 and k = 0.89 during the postembryonic period.

Animals↗
PubMedDate not supplied

[Effect of temperature on the rate of oxygen consumption during the second half of embryonic and early postembryonic development of European pond turtle Emys orbicularis (Reptilia: Emydidae)].

Oxygen consumption by eggs of European pond turtle was determined at two constant incubation temperatures of 25 and 28 degrees C during the second half of embryogenesis. During development at both temperatures, the rate of oxygen consumption initially increased to remain constant during the last quarter of embryogenesis. The difference between the rates of oxygen consumption at these temperatures decreased during the studied period. The coefficient Q10 for the rate of oxygen consumption decreased from 9 to 1.7. At an incubation temperature of 28 degrees C, the changes in the rate of oxygen consumption in response to a short-term temperature decrease to 25 degrees C or increase to 30 degrees C depended on the developmental stage and were most pronounced at the beginning of the studied period. During late embryonic and first 2.5 months of postembryonic development, the rate of oxygen consumption did not significantly differ after such temperature changes. The regulatory mechanisms formed during embryonic development are proposed to maintain the level of oxygen consumption during temperature changes.

Animals↗
PubMedDate not supplied

[The macrosystematics of mammals according to energy metabolism criteria].

Criteria of evolutionary progress and complexity of organization have been proposed on the basis of the data on energetic metabolism. These criteria can serve as a basis of macrosystematics of mammals at the level of orders. The orders with the known data on energetic metabolism have been ranged.

Animals↗
PubMedDate not supplied

[Energy metabolism and the direction of evolutionary progress in the class of mammals].

The data on dependence of standard metabolism on body weight in 518 mammalian species have been summarized. Standard metabolism differs in representatives of different classes and families. The higher it is, the more complicated is the organization of the animals. Comparison of standard metabolism in different classes of mammals with the time of their paleontological origin demonstrates that evolutionary process in mammals was directed towards the increase in energetic metabolism of animals.

Animals↗
PubMedDate not supplied

[The lifespan and Rubner constant at different temperatures in Drosophila melanogaster].

According to the Rubner's hypothesis, the total amount of oxygen consumed during life is constant for animals. This value is designated as the Rubner constant. Experimental data on the energetic exchange and life span in D. melanogaster allowed to conclude that the total oxygen consumption during the imaginal stage and during the whole ontogeny was not constant and changed under the influence of environmental temperature factor.

Animals↗
PubMedDate not supplied

Respiration during wound regeneration and healing in the planarian worm Dendrocoelum lacteum.

The intensity of respiration of the body fragments of the planarian after its division anteriorly and posteriorly to the pharynx was studied. After division anteriorly to the pharynx regeneration takes place. During regeneration of the anterior fragment respiration increases in the first day after the operation and at the differentiation stage. During regeneration of the posterior fragments the oxygen consumption is unchanged. Healing of the wound after division of the planarian posteriorly to the pharynx is accompanied by intensification of respiration during the first two days after the operation. Comparison of regeneration and healing of the wound in fragments of equal weight shows that in the initial stages the intensity of respiration was the same. A significant difference is found at the stage of differentiation of the regenerating worm, when the regenerating fragments have a higher intensity of respiration than fragments unable to regenerate.

Animals↗