Russian Journal of PhysiologyRussian Journal of PhysiologyРоссийский физиологический журнал им. И.М. Сеченова0869-81392658-655XThe Russian Academy of Sciences69825610.7868/S2658655X25110083EXPERIMENTAL ARTICLESЭКСПЕРИМЕНТАЛЬНЫЕ СТАТЬИResearch ArticleChanges in Barrier Properties of the Rat Jejunum and Colon after Hypobaric HypoxiaИЗМЕНЕНИЕ БАРЬЕРНЫХ СВОЙСТВ ТОЩЕЙ И ТОЛСТОЙ КИШКИ КРЫСЫ ПОСЛЕ ГИПОБАРИЧЕСКОЙ ГИПОКСИИFedorovaA. AФедороваА. АGankeD. DГанкеД. ДBikmurzinaA. EБикмурзинаА. ЕKravtsovaV. VКравцоваВ. ВKrivoiI. IКривойИ. ИMarkovA. GМарковА. Гa.markov@spbu.ruSaint Petersburg State UniversityСанкт-Петербургский государственный университетPavlov Institute of Physiology of the Russian Academy of SciencesИнститут физиологии им. И.П. Павлова РАН1511202511111VOL 111, NO11 (2025)ТОМ 111, №11 (2025)1814182709122025Copyright ©; 2025, Russian Academy of SciencesCopyright ©; 2025, Российская академия наук2025Russian Academy of SciencesРоссийская академия наукhttps://journals.eco-vector.com/0869-8139/article/view/698256

Barrier properties of intestinal epithelium play an important role in maintaining homeostasis, but become vulnerable in case of oxygen deficiency. In this work, the effect of hypobaric hypoxia (altitudes of 3000 and 6000 m) on the morphological parameters and barrier function of the small and large intestines of rats was investigated. The experiments were carried out using a pressure chamber and included histological analysis, electrophysiological measurements in a USsing chamber, assessment of the level of tight junction proteins (claudins-1 and -2) by Western blot and their localization by immunohistochemistry. It was found that hypobaric hypoxia causes segment-specific changes in morphometric parameters, barrier characteristics and the level of claudins. In the jejunum, the structure of the villi was disrupted and the level of claudin-2 decreased, in the colon, the depth of crypts changed, the level of claudin-1 and transepithelial resistance decreased. Partial recovery of functions was observed 24 h after exposure to hypoxia (3000 m), whereas no adaptation in the colon occurred after exposure to more severe hypoxia (6000 m). The data obtained highlight the high sensitivity of the intestinal barrier to hypoxic stress and its different response depending on the anatomical segment. The results may be useful in developing preventive strategies aimed at protecting the intestinal barrier under hypoxic conditions, including high-altitude expeditions or pathological conditions associated with impaired oxygen supply.

Барьерные свойства кишечного эпителия играют важную роль в поддержании гомеостаза, однако становятся уязвимыми при кислородной недостаточности. В данной работе исследовано влияние гипобарической гипоксии (соответствующей подъему на высоты 3000 и 6000 м) на морфологические параметры и барьерную функцию тощей и толстой кишки крыс. Эксперименты проводились с использованием барокамеры и включали в себя гистологический анализ, электрофизиологические измерения в камере Уссинга, оценку уровня белков плотных контактов (клаудинов-1 и -2) методом вестерн-блотинга и их локализацию методом иммуногистохимии. Установлено, что гипобарическая гипоксия вызывает время- и сегмент-специфические изменения морфометрических параметров, барьерных характеристик и уровня клаудинов. В тощей кишке через 3 ч нарушалась структура ворсинок и снижался уровень клаудина-2, в толстой – изменялась глубина крипт, снижался уровень клаудина-1 и трансэпителиальное сопротивление. Через 24 ч после воздействия гипоксии (3000 м) наблюдалось частичное восстановление функций тощей кишки, тогда как после воздействия более выраженной гипоксии (6000 м) адаптация в толстой кишке не наступала. Полученные данные подчеркивают высокую чувствительность кишечного барьера к гипоксическому стрессу и его различную реакцию в зависимости от анатомического сегмента. Результаты могут быть полезны при разработке превентивных стратегий, направленных на защиту кишечного барьера в условиях гипоксии, включая высотные экспедиции или патологические состояния, связанные с нарушением кислородного снабжения.

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