Pengaruh Pemberian Timbal (Pb) terhadap Kadar Malondialdehyde (MDA) Plasma Mencit

Abstract

Lead is widely found in our environment. Human are exposed to this metal from numerous sources, including contaminated air, water, soil and food. There are many studies that have shown that lead causes oxidative stress by inducing the generation of reactive oxygen species and reducing the anti-oxidant defense system. Lipid peroxidation increases because of impaired oxidant and anti-oxidant balance, measured by malondialdehyde levels. The current study investigates the effect of lead administration in various concentrations against lipid peroxidation. Twenty four male mice, 30-40 g body weight were divided into six groups. Group I served as control, group II to VI were given lead acetate at doses of 5, 10, 20, 40 and 80 mg/kg body weight respectively. After four weeks, plasma malondialdehyde levels and the number of erythrocytes were measured. An increase in plasma malondialdehyde levels observed in groups II to VI as compared with control, was not statistically significant (p=0,6). The increased plasma malondialdehyde levels in accordance to the increased concentration of lead administered, with the exception of group VI. The decrease in erythrocyte count observed in groups II to VI as compared with control, was not significant (p=0,1). Increased plasma malondialdehyde levels were negatively correlated with erythrocyte count (p=0,04). Lead interferes with physiological and biochemical functions related to oxidative stress. The trend to increased plasma malondialdehyde levels along with the decreased erythrocyte count as the dose of lead increased supports this statement.

Pb dijumpai tersebar di lingkungan kita. Manusia terpapar logam ini dari berbagai sumber seperti udara, air, tanah dan makanan yang terkontaminasi. Terdapat banyak penelitian menunjukkan bahwa Pb menyebabkan stres oksidatif dengan meningkatkan pembentukan reactive oxygen species dan menurunkan sistem anti-oksidan. Peroksidasi lipid meningkat karena terganggunya keseimbangan oksidan dan anti-oksidan, yang diukur dengan kadar malondialdehyde. Penelitian ini bertujuan mengetahui pengaruh pemberian berbagai konsentrasi Pb terhadap peroksidasi lipid. Dua puluh empat mencit jantan dengan berat 30-40 g dibagi dalam enam kelompok. Kelompok I sebagai kontrol, kelompok II sampai VI berturut-turut mendapat Pb asetat dosis 5, 10, 20, 40 and 80 mg/kg berat badan. Setelah empat minggu, dilakukan pengukuran kadar malondialdehyde plasma dan hitung jumlah eritrosit. Peningkatan kadar malondialdehyde pada kelompok II sampai VI bila dibandingkan dengan kontrol, secara statistik tidak bermakna (p=0,6). Peningkatan tersebut sejalan dengan peningkatan konsentrasi Pb yang diberikan, kecuali kelompok VI. Hitung jumlah eritrosit menunjukkan penurunan jumlah eritrosit pada kelompok II sampai VI bila dibandingkan dengan kontrol, tidak bermakna secara statistik (p=0,1). Peningkatan kadar malondialdehyde plasma berkorelasi negatif dengan jumlah eritrosit (p=0,04). Pb menyebabkan gangguan fungsi fisiologis dan metabolisme melalui efek stres oksidatif. Hal tersebut terlihat dari adanya kecendrungan peninggian kadar malondialdehyde plasma yang diikuti dengan penurunan jumlah eritrosit oleh peningkatan dosis Pb.