RU2460150C1 - Method of typing adaptive strategy in experiment - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: oxygen consumption, carbon dioxide release, rectal temperature are recorded in the primary metabolism environment. That is followed by unfavourable exposure and repeated measurement of these values. The initial oxygen consumption and carbon dioxide release are accepted as a zero value, while the rectal temperature is used in an absolute value. If observing increasing the values, an adaptive strategy of resistance is shown, while decreasing the values shows an adaptive strategy of tolerance.

EFFECT: method enables higher accuracy of typing and evaluating the manifestation of the adaptive strategy of an animal's body in experiment.

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Description

The present invention relates to medicine, namely to experimental surgery and diagnosis, and can be used to determine the type and severity of the strategy for adapting the body to an unfavorable situation.

A known method for determining an adaptation strategy, including determining the oxygen consumption of an organism by means of a Shaternikov type metabolimeter. Moreover, an increase in oxygen consumption indicates the implementation of the adaptive strategy of resistance, a decrease in oxygen consumption indicates the implementation of the adaptive strategy of tolerance [Bocharov S.N., Kulinsky V.I. The body's defensive strategies in anesthesiology and resuscitation. - Irkutsk, 2003. - S.20-21].

The disadvantages of this method include its low accuracy, since there is no registration of the initial state of the organism and only one indicator is used to determine the type of adaptation strategy.

The closest in technical essence to the proposed one is a method for determining the type of adaptation strategy by measuring the body’s oxygen consumption using a Shaternikov type metabolimeter. The authors of the known method established two adaptation strategies. Thus, the implementation of a strategy of active counteraction or “resistance” is accompanied by an increase in metabolic activity, which is reflected in an increase in the body’s consumption of oxygen, while the implementation of a strategy of passive counteraction or “tolerance”, on the contrary, reduces metabolic activity and oxygen consumption. So, 30 minutes after administration of adrenaline at a dose of 5.5 μmol / kg to rats, an increase in oxygen consumption of 25% was observed, which indicated the implementation of the adaptive resistance strategy. 30 minutes after the administration of 3.8 µmol / kg of clonidine to rats, a 50% decrease in oxygen consumption was recorded, which confirmed the implementation of the adaptation strategy of tolerance [Bocharov S. N., Kulinsky V. I. The body's defensive strategies in anesthesiology and resuscitation. - Irkutsk, 2003. - S.20-21].

The disadvantages of this method, as well as similar, should include the fact that it does not contain a description of the initial state. Due to the absence of such a description, the accuracy of evaluating subsequent changes in metabolic activity and conclusions about the implementation of one of two adaptation strategies are reduced. Using a single indicator - oxygen consumption as an integral criterion for metabolic intensity is correct in the absence of hypoxia, which severely limits the possibilities of the method, since hypoxia is an important mechanism for the pathogenesis of most diseases.

The task of the invention is to develop a method for determining the type of adaptation strategy and its severity in the experiment.

The technical result of the proposed method is to increase the accuracy of determining the type and quantitative assessment of the severity of the adaptation strategy of the animal organism in the experiment.

The technical result of the proposed method for determining the type of adaptation strategy in the experiment includes the creation of adverse conditions for the life of the animal and the registration of changes in oxygen consumption.

New in the implementation of the technical result of the proposed method is that to determine the type and severity of the adaptation strategy, a comparison of the metabolic activity of the body before exposure, i.e. in conditions of the main exchange of an intact animal, and after exposure. The metabolic activity of the body of an experimental animal is determined by three indicators: oxygen consumption, carbon dioxide emission and rectal temperature.

The difference of the proposed method also lies in the fact that with an increase in the values of these indicators compared with the initial ones, an adaptive strategy of resistance is established, and with a decrease, an adaptive strategy of tolerance is established.

A comparative analysis of the proposed solution and the prototype shows that the proposed method differs from the known above methods. These differences allow us to conclude that the claimed technical solution meets the criteria of the invention of "novelty."

The inventive method allows you to determine the type and severity of the strategy of adaptation to an unfavorable situation, which, in turn, makes it possible to predict the course of the disease and adjust treatment tactics.

So, the authors of the proposed method found that in laboratory animals, chinchilla rabbits, under conditions of multiple skeletal trauma, against the background of standard treatment (NSAID analgesia, infusion therapy, antibiotic prophylaxis), an adaptation tolerance strategy is implemented, characterized by a decrease in metabolic activity. In laboratory animals (chinchilla rabbits) that died within a week after the injury, on the first day after the injury, a more pronounced decrease in all three indicators characterizing metabolic activity was recorded: oxygen consumption (by 18% compared with surviving animals), carbon dioxide emission (by 15%), rectal body temperature (by 1.2 ° C).

The authors of the proposed method also found that an increase in the values of these indicators compared with the original corresponds to the adaptive resistance strategy.

The difference of the proposed method also lies in the fact that in addition to a qualitative assessment of the type of adaptation strategy, it allows you to quantify the severity of adaptive changes in metabolism. This is achieved by comparing the initial indicators of the minimum normal metabolic activity with indicators of metabolic activity after adverse effects. Moreover, the authors of the proposed method, the initial indicators are equated to zero values, which made it possible to quantify the severity of the adaptation strategy.

To determine the minimum normal metabolic activity, the state of the main metabolism of the intact organism is selected, while the metabolic activity is evaluated by three indicators: oxygen consumption, carbon dioxide emission and rectal temperature.

The authors of the proposed method, the search for solutions known in medicine showed that the results were not found in the known solutions and were not previously used for a qualitative and quantitative assessment of the type and severity of the adaptation strategy, therefore, the proposed method meets the patentability criterion of "inventive step".

The method comprising the claimed invention relates to medicine and is intended for use in experimental surgery. The possibility of its implementation is confirmed by the methods and means described in the application. The proposed method ensures the achievement of the technical result set by the applicant, namely, it increases the accuracy of determining the type and quantifies the severity of the adaptive strategy of the body in adverse conditions. From the above it follows that the claimed invention meets the condition of patentability "industrial applicability".

The inventive method for determining the type of strategy for adaptation of the animal organism is as follows.

In an experiment in rabbits of the chinchilla breed, under conditions of basic metabolism, i.e. 14-16 hours after the last meal, at a comfort temperature of 18-20 ° C, with the exception of sharp unusual stimuli, oxygen consumption, carbon dioxide emission and rectal temperature are measured.

The measurement of gas exchange is as follows: the laboratory animal is placed in an airtight chamber. Using gas analyzers, the sensors of which are located inside the chamber, determine the concentration of oxygen and carbon dioxide - the initial and after 1 h. Calculate the difference in the concentrations of the studied gases by the formulas:

,

,

- разница концентраций кислорода, %;Where

- difference in oxygen concentrations,%;

- исходная концентрация кислорода, %;

- initial oxygen concentration,%;

- концентрация кислорода через 1 ч, %;

- oxygen concentration after 1 h,%;

- разница концентраций углекислого газа, %;

- the difference in the concentration of carbon dioxide,%;

- исходная концентрация углекислого газа, %;

- initial concentration of carbon dioxide,%;

- концентрация углекислого газа через 1 ч, %.

- carbon dioxide concentration after 1 h,%.

Indicators of oxygen consumption (VO ₂ ) and carbon dioxide emissions (VCO ₂ ) are calculated by the formulas, respectively:

- разница концентрации кислорода на этапе исследования, %;Where

- difference in oxygen concentration at the research stage,%;

- разница концентрации кислорода в условиях основного обмена, %;

- the difference in oxygen concentration in the conditions of the main exchange,%;

- разница концентрации углекислого газа на этапе исследования, %;

- the difference in the concentration of carbon dioxide at the research stage,%;

- разница концентрации кислорода в условиях основного обмена, %.

- the difference in oxygen concentration in the conditions of the main exchange,%.

The authors of the proposed method offer the values of the indicators of oxygen consumption and carbon dioxide emission in the conditions of the main metabolism to accept equal to zero, then at the stages of the study these indicators will reflect their relative (percentage) change to the corresponding indicators obtained in the conditions of the main exchange. At the same time, a positive value of the indicators indicates an increase in metabolic activity and, accordingly, the implementation of the adaptive strategy of resistance, and a negative value of the indicators indicates a decrease in metabolic activity and the implementation of the adaptive strategy of tolerance. The deviation of these indicators from the zero level characterizes the severity of the implementation of one of two adaptation strategies.

Rectal body temperature is measured by an electronic thermometer with a flexible tip when it is immersed in the rectum of an animal to a depth of 4-5 cm. An increase in rectal temperature at the study stage compared with the value of the indicator under conditions of basic metabolism indicates an increase in metabolic activity, and a decrease in indicator indicates a decrease metabolic activity of the body of an experimental animal.

Experimental studies of the authors of the proposed method allowed to establish:

- direct strong correlation between the indicators of carbon dioxide emission and oxygen consumption (Spearman's rank correlation coefficient r _s = 0.84 at p <0.001);

- direct strong correlation between the release of carbon dioxide and internal temperature (r _s = 0.73 at p <0.001);

- a direct correlation of the average force between oxygen consumption and internal temperature (r _s = 0.66 at p <0.001).

Established by the authors of the proposed method, a pronounced direct correlation of all three indicators used to characterize the activity of metabolism, allows to increase the accuracy of determining the type and severity of the adaptation strategy.

When implementing the proposed method, surgery is performed as follows. Under general anesthesia (intramuscular premedication: atropine 0.1% -0.5 ml, analgin 50% -1.0 ml, diphenhydramine 1% -0.5 ml, sibazon 0.5% -0.5 ml; intramuscular anesthesia: ketamine 5% -0.7 ml, droperidol 0.25% -0.3 ml) of the rabbit is fixed on Sechenov's table in the supine position. The right forelimb is trimmed and three times treated with an antiseptic solution. Using a device for dividing a segment into levels, locations of transosseous elements are determined, after which an external fixation device is applied to the right front limb. An osteotomy of the forearm bones is performed through a 0.5 cm incision with a chisel so that the proximal fragment is fixed by the proximal and middle base supports, and the distal support is connected to the middle by means of hinges to form a physiological bend.

The left hind limb is trimmed, three times treated with an antiseptic solution. Using a device for dividing a segment into levels, venues of transosseous elements are determined, after which an external fixation device is superimposed on the left hind limb. An osteotomy of the lower leg bones is performed through a 0.5 cm incision with a chisel so that the proximal fragment is fixed by the proximal and middle base supports, the distal support is connected to the middle by means of hinges to form a physiological bend.

Standard postoperative treatment includes intramuscular analgesia with 50% analgin at a daily dose of 400-500 mg / kg / day. within 5 days. after surgery, antibiotic prophylaxis with lincomycin 50-70 mg / kg / day. and infusion therapy with a glucose solution of 5% in a daily dose of 50-60 ml / kg / day. within 3 days. after operation.

In the postoperative period, the measurement of oxygen consumption, carbon dioxide and rectal temperature is carried out in the same way as before the operation.

The proposed method is illustrated by an example of a specific implementation.

In an experiment on 22 rabbits of the chinchilla breed, a model of multiple skeletal injury was reproduced. For this, under general anesthesia, laboratory animals were superimposed with external fixation devices on the right forearm and left lower leg, followed by osteotomy of the bones of the corresponding limb segments. Standard postoperative treatment included analgesia, antibiotic prophylaxis, and infusion therapy.

All laboratory animals before surgery in the main exchange conditions, as well as on the first, third and seventh days after the operation in an airtight chamber using gas analyzers (Oldham OX-2000 and C-2000), oxygen consumption and carbon dioxide emission were determined. Rectal body temperature was measured by an electronic thermometer outside the chamber.

It was found that on the first day after the operation, against the background of standard treatment, there was a statistically significant decrease in oxygen consumption, carbon dioxide emissions and internal body temperature (Table 1. Data are presented as median, 25th and 75th percentiles).

Table 1. Dynamics of oxygen consumption, carbon dioxide emission and rectal temperature in chinchilla rabbits under conditions of multiple skeletal injury indicators before surgery after operation 1 day 3 days 7 days oxygen consumption,% Me 0% -16%* -10%* -6% * P ₂₅ 0% -33% -eighteen% -24% P ₇₅ 0% -8% -four% -3% carbon dioxide emission,% Me 0% -28% * -17% * -19%* P ₂₅ 0% -thirty% -25% -27% P ₇₅ 0% -eleven% -7% -7% rectal temperature, ° С Me 39.3 38.0 * 39.0 * 39.2 P ₂₅ 39.1 37,4 37.9 37.8 P ₇₅ 39,4 38.6 39.2 39.5 * p <0.05 compared with the value of the indicator before surgery.

On the third day of the postoperative period, the decline was less pronounced, but also statistically significant.

By the seventh day after the operation, the indicator of internal body temperature tended to the initial level, in contrast to the indicators of oxygen consumption and carbon dioxide emissions, which remained 6% and 19% respectively below the initial values.

The obtained dynamics of the indicators characterizing metabolic activity testified to the realization in laboratory animals under conditions of multiple skeletal trauma, against the background of standard treatment, an adaptive tolerance strategy.

Mortality in the experimental group for 7 days. after surgery was 54.5%.

It is known that a traumatic disease that develops after multiple skeletal trauma is a difficult clinical situation. At the same time, it follows from the data obtained that almost half of the animals were able to overcome this difficult situation under standard postoperative therapy. To identify possible differences in adaptation between surviving and dead animals, the authors compared the dynamics of indicators characterizing metabolic activity in these two subgroups. Table 2 shows the comparative dynamics of indicators characterizing metabolic activity in the subgroups of surviving and dead animals.

From the data given in table 2 it follows that in laboratory animals that died during the first 7 days. after the operation, there was a statistically significantly more pronounced decrease in oxygen consumption, carbon dioxide and internal temperature throughout the postoperative period.

An analysis of the results indicates that a more severe, prognostically unfavorable clinical situation is accompanied by a deeper inhibition of metabolism as part of the adaptive tolerance strategy.

Thus, the inventive method made it possible to establish that in laboratory animals - chinchilla rabbits, under conditions of multiple skeletal trauma, an adaptation tolerance strategy is implemented against a background of standard postoperative treatment, characterized by a decrease in metabolic activity. The dynamics of metabolic activity during the first week after surgery is shown. A comparative analysis of oxygen consumption, carbon dioxide emission and internal temperature in the subgroups of those who died during the week after multiple skeletal injuries and surviving animals revealed a difference in metabolic activity on the first day after the injury. The deep inhibition of metabolism in the subgroup of dead animals confirms the role of the adaptive strategy of tolerance, as a "last chance", the method of long-term existence in an insurmountable, extremely difficult clinical situation.

The choice of the state of the main metabolism of an intact animal to characterize normal metabolic activity, i.e. the zero point of adaptation, allows you to draw correct conclusions about the type and severity of the adaptation strategy in an unfavorable situation.

The obtained data on the difference in metabolic activity in subgroups of animals with different outcomes of the disease make it possible to use the inventive method to determine the prognosis of severe injury and, accordingly, the need for therapeutic measures.

Using three indicators to determine the metabolism activity allows to increase the accuracy of the type determination method and to quantify the severity of adaptive changes.

Claims (1)

A method for determining the type of adaptation strategy in an experiment, including the creation of adverse conditions for the animal’s life and recording changes in oxygen consumption, characterized in that the oxygen consumption, carbon dioxide emission, rectal temperature are recorded first under the conditions of the main metabolism, after which an adverse effect is performed and re-determined the values of these indicators, while the initial indicators of oxygen consumption and carbon dioxide emissions are taken they are taken as zero values, and the rectal temperature indicator is used in absolute terms, and with an increase in the values of all indicators, the adaptive strategy of resistance is established, and with a decrease, the adaptive strategy of tolerance.