Aktivitas Makrofag Meningkat Pada Aorta Tikus Hiperkolesterolemia

Abstract

Aterosklerosis merupakan, kondisi inflamasi kronik, faktor resiko penyakit kardiovaskular disebabkan oleh tingginya kadar kolesterol. Tujuan penelitian ini mengevaluasi peran mieloperoksidase (MPO) dan makrofag di aorta dan jantung tikus yang diinduksi hiperkolesterolemia. Penelitian ini dilakukan pada Maret–Agustus 2016 di Laboratorium Farmakologi dan Bioteknologi Institut Teknologi Bandung. Tikus dikelompokkan menjadi kelompok normal dan hiperkolesterolemia. Induksi hiperkolesterolemia dilakukan dengan pemberian pakan tinggi kolesterol, kolesterol murni, asam kolat dan propiltiourasil (KKT) selama 5 bulan. Kolesterol total diukur sebelum induksi, pertengahan, dan setelah induksi. HDL, trigliserida (TG), LDL, indeks aterogenik (IA), jumlah sel darah merah dan sel darah putih diukur setelah induksi. Deteksi ekspresi mieloperoksidase (MPO) dan CD68 pada aorta dan jantung dilakukan dengan metode dot blot dan ELISA. Induksi hiperkolesterolemia selama 5 bulan menghasilkan kadar kolesterol total (364,10±148,46 mg/dL), HDL (7,90±1,29 mg/dL), LDL (307,47±116,91 mg/dL), dan Indeks Aterogenik (1,04±0,23). Kadar kolesterol yang tinggi meningkatkan jumlah sel darah putih yang bersirkulasi namun tidak mempengaruhi jumlah sel darah merah. Jumlah makrofag yang berada di jaringan aorta dan jantung kelompok hiperkolesterolemia meningkat secara signifikan dibanding dengan kelompok normal. Namun, peningkatan aktivitas makrofag yang diukur dari ekspresi MPO hanya teramati pada aorta hewan hiperkolesterolemia, tidak pada jantung. Simpulan, aktivitas makrofag meningkat hanya pada aorta hewan hiperkolesterolemia diduga berperan dalam pembentukan plak ateroma di aorta. 

Kata kunci: Aorta, CD68, hiperkolesterolemia, makrofag, mieloperoksidase

Macrophage Activity Increases in Hypercholesterolemia Rat Aorta

Atherosclerosis, which is an inflammatory chronic condition, is one of the major risk factors of cardiovascular disease caused by hypercholesterolemia. This study aimed to evaluate role of myeloperoxidase (MPO) and macrophage in aorta and heart of rat hypercholesterolemia. This research was conducted in March–August 2016 at Pharmacology and Biotechnology Laboratory of Institut Teknologi Bandung. Rats were divided into normal and hypercholesterolemia groups. Hypercholesterolemia was induced by cholesterol feeding and CCT (cholesterol, cholic acid and propiltiourasil) oral administration for 5 months. Total cholesterol was measured before induction (T0), in the middle (T2.5), and after induction (T5). HDL, triglyceride (TG), LDL, aterogenic index (IA), red blood, and white blood cell count was measured after induction (T5). Success of induction was proven by the elevation of cholesterol total value of hypercholesterolemia group compared to normal group. Myeloperoxidase (MPO) and CD68 in aorta and heart hypercholesterolemia rat was detected by dot blot and ELISA method. Hypercholesterolemia group showed significant differences in total cholesterol value (364.10±148.46 mg/dL), HDL value (7.90±1.29 mg/dL ), LDL value (307.47±116.91) and Atherogenic Index (1.04±0.23). High level of cholesterol increases circulating white blood cells but have no effect on  circulating red blood cells. Macrophage in the  hypercholesterolemia group increased significantly compared to the normal group. However, the increase in macrophage activity identified throughMPO expression was only seen in hypercholesterolemic aorta but not  in the heart. It is concluded that macrophage activities increase in the aortic tissue, but  not in the heart tissue of the hypercholesterolemia group, which may contribute to the formation of atheroma plaque in aorta. 

Key words: Aorta, CD68, hypercholesterolemia, macrophage, myeloperoxidase