METHODOLOGY OF JOINT ANALYSIS OF CONCURRENT PATHOLOGICAL PROCESSES IN LABORATORY ANIMALS

Abstract

This article sets out to analyze possible approaches to assessing the joint effect of simultaneously occurring and mutually aggravating pathological processes. In medicine of extreme environments, such examples include the joint effect of hypoxia and hyperthermia (desert mountain environments); hypoxia and low temperatures (high altitude locations, mountain stations in Antarctica); intense physical exertion and endogenous or combined hyperthermia (work in insulating protective equipment or in humid tropics); respiration using specialized hypoxic helium-oxygen gas mixtures under the conditions of hyperbaria and deep-sea dives; exposure to weightlessness and vestibular loads during spacefl ight; etc. In clinical practice, such conditions may be referred either to the phenomenon of comorbidity, when the pathological processes have common pathogenesis links, or to the phenomenon of polymorbidity, when there is no clear pathogenetic link between the processes. This research shows that clinical methods currently used for assessing comorbidity cannot be directly applied in preclinical studies performed with the participation of laboratory animals. A methodology for assessing the interaction of two experimentally simulated pathological processes in one group of animals based on a two-factorial experiment is presented. It is shown that the phenomenon of mutual aggravation is manifested through a signifi cant interaction between the controlled factors, thus requiring an additive or supra-additive effect according to the key parameters of the experimental model. The feasibility of the proposed approach was tested experimentally by evaluating the interaction of two independent simulated processes, i.e. chronic periodic moderate normobaric hypoxia (typical of sleep apnea) and non-alcoholic fatty liver disease. It was established that the simulated processes are mainly realized as independent factors. High-calorie lipid-carbohydrate nutrition causes a predominant rearrangement of carbohydrate metabolism in the tissues and has a partial antagonistic effect on the metabolic manifestations of chronic hypoxic effects.