Otak merupakan organ yang memiliki kebutuhan oksigen dan glukosa tertinggi di tubuh. Rendahnya tekanan oksigen pada otak dapat memicu terjadinya kerusakan pada sel otak bahkan kematian sel. Hipoksia merupakan kondisi penurunan kadar oksigen pada organ, jaringan atau sel. Hipoksia yang diberikan pada kadar dan waktu tertentu dapat menimbulkan respons adaptasi tubuh sehingga kondisi hipoksia dapat ditanggulangi. Salah satu respons adaptasi yang dilakukan adalah autofagi. Autofagi adalah suatu proses degradasi dan daur ulang molekul sitoplasmik dan organel seperti mitokondria dengan bantuan lisosom yang berperan dalam menjaga homeostasis seluler. Penelitian ini dilakukan untuk mengetahui efek pemberian hipoksia hipobarik intermiten terhadap aktivitas autofagi sel melalui ekspresi protein LC3 dan mTOR pada jaringan otak tikus. Penelitian ini menggunakan sampel jaringan otak tikus jenis Sprague-Dawley. Tikus dibagi dalam lima kelompok, yaitu kelompok kontrol, kelompok hipoksia 1 kali (HHI 1), HHI 2, HHI 3 dan HHI 4. Setiap kelompok hipoksia akan dimasukan dalam hypobaric chamber dan dibawa sampai ketinggian 25.000 kaki selama 5 menit. Tikus kemudian dikorbankan dan dilakukan pengukuran ekspresi protein LC3 dan mTOR menggunakan metode ELISA. Ekspresi protein LC3 juga dianalisis dengan IHK. Hasil menunjukkan bahwa pemberian perlakuan hipoksia hipobarik intermiten mampu meningkatkan ekspresi protein LC3 dan mempertahankan ekspresi mTOR. Hasil pulasan IHK menunjukkan ekspresi protein LC3 lebih tinggi pada bagian cerebellum otak dibandingkan dengan bagian cerebrum pada setiap kelompok.

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The brain is an organ with the highest demand for oxygen and glucose in the body. Insufficient oxygen pressure in the brain can lead to damage to brain cells and even cell death. Hypoxia is a condition characterized by a decrease in the oxygen levels in organs, tissues, or cells. Hypoxia, when applied at specific levels and durations, can induce adaptive responses in the body, allowing it to cope with the hypoxic conditions. One such adaptive response is autophagy. Autophagy is a cellular process involving the degradation and recycling of cytoplasmic molecules and organelles, including mitochondria, facilitated by lysosomes. This process plays a crucial role in maintaining cellular homeostasis. This study aimed to investigate the effects of intermittent hypobaric hypoxia on autophagic activity in brain cells by assessing the expression of proteins LC3 and mTOR during hypoxic conditions. The experimental subjects were Sprague-Dawley rats, and they were divided into five groups: a control group, and four groups subjected to intermittent hypobaric hypoxia (IHH) for varying durations (IHH1, IHH2, IHH3, and IHH4). Each IHH group was exposed to a hypobaric chamber at an altitude of 25,000 feet for 5 minutes. Subsequently, the rats were sacrificed, and the expression of LC3 and mTOR proteins was measured using ELISA. The LC3 protein expression was also analyzed through immunohistochemistry (IHC). The results showed that intermittent hypobaric hypoxia treatment increased the expression of LC3 protein and maintained mTOR expression. Additionally, IHC feedback indicated higher LC3 protein expression in the cerebellum region compared to the cerebrum in each experimental group.