THE JOURNAL OF TROPICAL LIFE SCIENCE OPEN ACCESS Freely available online VOL. 6, NO. 2, pp. 65 - 68, May 2016 Submited August 2015; Revised February 2015; Accepted April 2016 Kinetic Parameters Analysis of Liver and Kidney Catalase Under the Influence of Cadmium (Cd) and Mercury (Hg) In Vitro Ellsa Anggun Karantika 1 , Supianur 1 , Edyson 2 , Eko Suhartono 2 * 1 Medical Education Program, Faculty of Medicine, University of Lambung Mangkurat, Banjarmasin, Indonesia 2 Medical Chemistry and Biochemistry Department, Faculty of Medicine, University of Lambung Mangkurat, Banjarmasin, Indonesia ABSTRACT Cadmium (Cd) and mercury (Hg) are toxic metals that afect human organs function, including liver and kidney. This toxic activity is because the heavy metal could induce oxidative stress and interfere antioxidant activities, including catalase (CAT). The present study was aims to evaluate the efect of Cd and Hg to liver and kidney CAT kinetic parameters in vitro. In this experiment, liver and kidney were taken from male rats ( Ratus novergicus). Sample the homogenized and divided into three groups with; T0 served as control which contains liver or kidney homogenate + H 2 O 2 , T1 which contains liver or kidney homogenate + H 2 O 2 + 0.03 mg/L CdSO 4 ; and T2 which contains liver or kidney homogenate + H 2 O 2 + 1 mg/L Hg. Solutions then incubated at 37ºC for 1 hour and then was prepared for CAT activity measurement. The CAT activity was measured using spectrophotometer at 240 nm. For measuring the kinetic parameters, diferent concentration of H 2 O 2 were used. The kinetics parameters (Km and Vmax) were calculated using Lineweaver-Burk plot. The results shows that Cd and Hg could decrease the afnity of CAT-H 2 O 2 complex which expressed by the higher Km and Vmax values. Also from the results, Cd has beter activity to decreased the afnity of CAT-H 2 O 2 complex than Hg. From this results, it can be concluded that Cd and Hg treatments could inhibit CAT activity in liver and kidney in vitro. Keywords: Cadmium (Cd), catalase, kinetic parameters, mercury (Hg) Heavy metal such as Cd and Hg are toxic metals that are widespread in the environment [1, 2]. These metals can occur as a results from natural, anthro- pogenic, and human sources [2, 3]. These heavy metals are not biodegradable, so as consequences these can ac- cumulate in living organisms [4]. Because of the nature of heavy metals tend to accumulate in living organ- isms, these metals can enter the food chain to humans [5]. Human exposure can cause many various efects to human organs, especially kidney and liver [6, 7]. The previous study had shown that chronic exposure to Cd could induce kidney damaged, manifested by protein- uria, glucosuria, aminoaciduria, and phosphaturia [8]. The Cd also lead to a liver damaged [9], both in acute and chronic exposure. Many studies has well docu- mented that Cd exposure could cause the swelling, necrosis, and degeneration of hepatocytes [10]. Besides Cd, Hg also well documented to induced liver and kid- ney damaged. The previous study had shown that Hg exposure will lead to kidney and liver cells necrosis [11, 12]. The basic mechanism of Cd and Hg toxicity is an activity to induce oxidative stress [13]. Cd and Hg also impair antioxidant defenses. These antioxidant de- fenses involving thiol-containing antioxidants and en- zymes, including CAT [14, 15]. CAT is a heme-containing enzyme and found in al- most all aerobically respiring organisms. CAT is an in- tracellular enzyme that can be found in all tissues and organs. The highest CAT concentrations are found in erythrocytes, liver, and kidney [16]. The main function of CAT catalyzes the conversion of hydrogen peroxide JTLS | J. Trop. Life. Science 65 Volume 6 | Number 2 | May | 2016 INTRODUCTION *Corresponding author: Eko Suhartono Medical Chemistry and Biochemistry Department, Faculty of Medicine, University of Lambung Mangkurat Jalan Brigjen H. Hasan Basri, Banjarmasin 75117, Indonesia E-mail address: ekoantioxidant@gmail.com How to cite: Karantika EA, Supianur, Edyson, Suhartono E (2016) Kinetic parameters analysis of liver and kidney catalase under the influence of cadmium (Cd) and mercury (Hg) in vitro. J. Trop. Life. Science 6 (2): 65 – 68. doi: 10.11594/jtls.06.02.01