Influence of circulatory and hemic hypoxia on cutaneous microcirculation

Objective. To establish the features of cutaneous microhemocirculation in conditions of circulatory and hemic hypoxia. Material and methods. Experiments were carried out on outbred rats, anesthetized by pentobarbital. Blood flow in the skin of the rat ear was recorded by laser Doppler flowmetry (LDF). Stages of the experiment: baseline; acute blood loss (30 % of estimated blood volume); reinfusion (autohemotransfusion in «control» group and infusion of modified gelatin solution in «Gelofusin» group); hemodilution with Gelofusin. The following parameters were analyzed: the mean value of blood flow (M, PU); the maximum (dominant) amplitude of blood flow oscillations (A_max) and the corresponding frequency (F_max) in the frequency band 0.01-0.4 Hz. The coefficient of oxygen delivery to the tissue site under investigation (D_tO₂) was used to assess the severity of hypoxia. Results. At the posthemorrhagic stage M, blood pressure (BP), hematocrit (Ht), D_tO₂ and F_max decreased along with an increase in A_max. F_max shifted from the myogenic frequency band at the baseline into the neurogenic band. A correlation was found between A_max and BP (r=-0,38; p<0,05). At the reperfusion stage, there was no intergroup difference in M, F_max, A_max, despite the higher values of BP, Ht and D_tO₂ in the «control» group. In comparison with the baseline At the «hemodilution» stage the values of M did not differ from the baseline against the background of lower values of Ht, D_tO2 and BP; A_max remained elevated, and F_max shifted into the myogenic band and did not differ from the baseline. Conclusion. Both blood loss and hemodilution are associated with an increase in the amplitude of fluxmotion. Mechanisms of fluxmotion stimulation are different: increasing the amplitude of fluxmotion in circulatory hypoxia is associated with the neurogenic regulatory mechanisms of microhemocirculation, while in hemic hypoxia it is associated with the myogenic mechanisms. Arterial hypotension is the main factor increasing the amplitude of fluxmotion during blood loss.

кожный кровоток, микроциркуляция, лазерная допплеровская флоуметрия, вейвлет-анализ, гипоксия, cutaneous blood flow, microcirculation, laser Doppler flowmetry, wavelet-analysis, hypoxia

1. Исраелян Л. А., Лубнин А. Ю. Эффективность и безопасность применения 6% гидроксиэтилированного крахмала 130/0,4 и 4% модифицированного жидкого желатина у нейрохирургических больных в условиях массивной интраоперационной кровопотери // Анестезиол. иреаниматол. - 2010. - № 4. - С. 50-54. [Israyelyan LA, Lubnin AYu. Effektivnost’ i bezopasnost’ primeneniya 6% gidroksietilirovannogo krakhmala 130/0,4 i 4% modifitsirovannogo zhidkogo zhelatina u neyrokhirurgicheskikh bol’nykh v usloviyakh massivnoy intraoperatsionnoy krovopoteri. Anesteziologiya i reanimatologiya. 2010;(4):50-54. (In Russ)].

2. Каркищенко Н. Н., Грачев С. В. Руководство по лабораторным животным и альтернативным моделям в биомедицинских исследованиях. - М.: Профиль - 2С, 2010. [Karkishchenko NN, Grachev SV. Rukovodstvopo laboratornym zhivotnym i al’ternativnym modelyam v biomeditsinskikh issledovaniyakh. Moscow: Profil’- 2S; 2010. (In Russ)].

3. Крупаткин А. И. Колебания кровотока - новый диагностический язык в исследовании микроциркуляции // Регионарное кровообращение и микроциркуляция. - 2014. - Т. 13. - № 1. - С. 83-99. [Krupatkin AI. Kolebaniya krovotoka - novyy diagnosticheskiy yazyk v issledovanii mikrotsirkulyatsii. Regionarnoye krovoobrashcheniye i mikrotsirkulyatsiya. 2014;13(1):83-99. (In Russ)].

4. Марино П. Л. Интенсивная терапия / пер. с англ. под общ. ред. А. П. Зильбера. - М.: ГЭОТАР-Медиа, 2010. [Marino PL. Intensivnaya terapiya. Per. s angl. pod obshch. red. A.P. Zil’bera. Moscow: GEOTAR-Media; 2010. (In Russ)].

5. Мороз В. В., Рыжков И. А. Острая кровопотеря: регионарный кровоток и микроциркуляция: обзор. Ч. I // Общая реаниматол. - 2016. - Т. 12. - № 2. - С. 66-89. doi: 10.15360/1813-9779-2016-2-56-65. [Moroz VV Ryzhkov IA. Acute Blood Loss: Regional Blood Flow and Microcirculation (Review, Part I). General Reanimatology. 2016;12(2):66-89. (In Russ)].

6. Мороз В. В., Рыжков И. А. Острая кровопотеря: регионарный кровоток и микроциркуляция: обзор. Ч. II // Общая реаниматол. - 2016. - Т. 12. - № 5. - С. 65-94. doi: 10.15360/1813-9779-2016-5-65-94. [Moroz VV Ryzhkov IA. Acute Blood Loss: Regional Blood Flow and Microcirculation (Review, Part II). General Reanimatology. 2016;12(5):65-94. (In Russ)].

7. Рыжков И. А., Новодержкина И. С., Заржецкий Ю. В. Сравнительные аспекты регуляции кожной и мозговой микроциркуляции при острой кровопотере // Общая реаниматол. - 2017. - Т. 13. - № 6. - С. 18-27. doi: 10.15360/1813- 9779-2017-6-18-27. [Ryzhkov IA, Zarzhetsky YV, Novoderzhkina IS. Comparative Aspects of the Regulation of Cutaneous and Cerebral Microcirculation During Acute Blood Loss. General Reanimatology. 2017;13(6):18-27. (In Russ)].

8. Aalkjoer C, Boedtkjer D, Matchkov V. Vasomotion - what is currently thought? Acta Physiol. (Oxf). 2011;202(3):253-269. doi: 10.1111/j.1748-1716.2011.02320.x.

9. Goldman D, Popel AS. A computational study of the effect of vasomotion on oxygen transport from capillary networks. J. Theor. Biol. 2001;209(2):189-199.

10. Iida N. Effects of vasomotion and venous pressure elevation on capillary-tissue fluid exchange across heteroporous membrane. Biorheology. 1990;27(2):205-224.

11. Intaglietta M. Vasomotion and flowmotion: physiological mechanisms and clinical evidence. Vasc Med. 1990;(1):101-112. doi: 10.1177/1358836X9000100202.

12. Li Z, Tam EW, Kwan MP, Mak AF, Lo SC, Leung MC. Effects of prolonged surface pressure on the skin blood flowmotions in anaesthetized rats - an assessment by spectral analysis of laser Doppler flowmetry signals. Phys. Med. Biol. 2006;51(10):2681-2694. doi: 10.1088/0031-9155/51/10/020.

13. Meyer C, de Vries G, Davidge ST, Mayes DC. Reassessing the mathematical modeling of the contribution of vasomotion to vascular resistance. J. Appl. Physiol. 2002;(92):888-889. doi: 10.1152/jappl.2002.92.2.888.

14. Mirhashemi S, Messmer K, Arfors KE, Intaglietta M. Microcirculatory effects of normovolemic hemodilution in skeletal muscle. Int J Microcirc Clin Exp. 1987;6(4):359-369.

15. Sakurai T, Terui N. Effects of sympathetically induced vasomotion on tissue-capillary fluid exchange. Am. J. Physiol. Heart. Circ. Physiol. 2006;291(4):1761-1767. doi: 10.1152/ajpheart.00280.2006.

16. Schmidt JA, Borgstrom P, Intaglietta M. Neurogenic modulation of periodic hemodynamics in rabbit skeletal muscle. J Appl Physiol. 1993;75(3):1216-1221. doi: 10.1152/jappl.1993.75.3.1216.

17. Schmidt JA, Breit GA, Borgstrom P, Intaglietta M. Induced periodic hemodynamics in skeletal muscle of anesthetized rabbits, studied with multiple laser Doppler flow probes. Int J Microcirc Clin Exp. 1995; 15(1):28-36. doi: 10.1159/000178946.

18. Schmidt-Lucke C, Borgstrom P Schmidt-Lucke JA. Low frequency flowmotion/(vasomotion) during pathophysiological conditions. Life Sci. 2002;71(23):2713-2728. doi: 10.1016/s0024-3205(02)02110-0.

19. Stefanovska A, Bracic M, Kvernmo HD. Wavelet analysis of oscillations in the peripheral blood circulation measured by laser Doppler technique. IEEE Trans Biomed Eng. 1999; 46(10):1230-1239. doi: 10.1109/10.790500.