Introduction. The extreme climatic and geographical factors of the North of Russia affect the metabolic responses of the body in the alien population, which distinguishes them from those of the indigenous inhabitants.

Materials and methods. It was conducted a study of the biochemical parameters of erythrocyte membranes in healthy men of two ethnic groups aged 20–30 years which undergoing routine medical examination in a regional hospital. There were examined 20 men of the alien population (Caucasians) and 20 men of the indigenous Chukchi population (Mongoloids). The group of alien population included men who had been living in the North for no more than 1–2 years. This indicates incomplete adaptation and the preservation of metabolism characteristic in Caucasians.

Results. There was carried out a comparative analysis of the quantitative composition of phospholipids, fatty acids of erythrocyte membranes, their size characteristics and hemolytic resistance to hemolytic effects in indigenous and alien populations of the North of the Russian Federation. It has been obtained the data on the ethnic characteristics of metabolic responses in representatives of two ethnic groups. In the indigenous population (Chukchi), there was a change in the ratio of phospholipid fractions in the erythrocyte membrane compared with those in the alien population. Along with this, there were differences in the fatty acid composition of lipids in erythrocyte membranes, which confirms the ethnic characteristics of indigenous and alien populations. These differences in the composition of polyunsaturated fatty acids in the structures of PC and PE suggest the appearance of modified molecular species of these fractions in the indigenous population.

Limitations. The study is limited to the number of persons examined, conducted medical examination in a district hospital.

Conclusion. Ethnic features in the phospholipid component of erythrocyte membranes in the indigenous population cause differences in the dimension characteristics of erythrocytes and an increasing in cell resistance to hemolytic effects. In our opinion, this is not a deviation from the norm, but one of the variants of human metabolism. The presence of ethnic characteristics must be taken into consideration when appointing a therapy and carrying out preventive measures in population groups of a specific geographical area.

Keywords: indigenous Chukchi population; Caucasian newly arrived population; erythrocytes; phospholipids; fatty acids; diameter; volume of erythrocytes; hemolytic stability

Compliance with ethical standards. All procedures performed in human studies comply with the ethical standards of the National Research Ethics Committee and the 1964 Helsinki Declaration and its subsequent changes or comparable ethical standards. Informed voluntary consent was obtained from each participant included in the study. The study was approved by the Ethics Commission of the V.I. Ilyichev Pacific Oceanological Institute FEBRAS (рrotocol No. 17 of 04/07/2021).

Contribution: Kushnerova N.F. – the concept and design of the study, writing a text; Momot T.V. – the concept and design of the study, collection material; Rakhmanin Yu.A. – editing; Ryzhova I.N. – collection of literature data; Fomenko S.E., Sprygin V.G. – collection material, statistical processing. All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version

Conflict of interest. The authors declare no conflict of interest.

Funding. The work was carried out within the framework of the state assignment of the Ilychev Pacific Oceanological Institute on the topic «Ecological and biogeochemical processes in ecosystems of the Far Eastern seas». State registration number 124022100077-0.

Received: October 1, 2025 / Revised: October 13, 2025 / Accepted: July 1, 2026 / Published: October 20, 2026