Background: Lactate dehydrogenase (LDH) is a ubiquitous enzyme commonly found in wide variety of organisms, including plants and microbes. LDH is involved in the interconversion of the pyruvate and NADH to lactate and NAD+. It is also called Hydroxybutyrate Dehydrogenase (HBD), due to the fact that it can catalyze the oxidation of hydroxybutyrate (1). Lactate dehydrogenase A (LDH-A, LDH muscle subunit, LDH-M) is involved in the final step of anaerobic glycoysis and catalyzes the conversion of L-lactate and NAD to pryruvate and NADH. While it is predominantly expressed in muscle tissue, it is hormonally regulated in rodents and overexpressed during mammary gland tumorigenesis (2). A mutation that cause deficiency in LDH-A has been implicated in exertional myoglobinuria (3).