Isoenzymatic diagnosis of filariae: a method for separation of lactate dehydrogenase isoenzymes from Molinema dessetae (Nematoda: Filarioidea)

Lactate dehydrogenase (LDH) is highly active in filariae and could be a valuable tool for phyllogeny studies. Unfortunately, the isoenzymatic diagnosis of filariae is often difficult for LDH because of a poor mobility of the enzymes in starch gels which are the most commonly used in such studies. We propose here a method to separate filarial LDH isoenzymes using disc electrophoresis. The experiments were carried out on male and female Molinema dessetae in order to compare their respective isoenzymes. The study of several parameters such as buffer systems, percentage of bisacrylamide and progression time led to optimize the enzyme separation. LDH from male and female filariae were compared to mammal LDH-H4 and LDH-M4. Five and four LDH isoenzymes were found, respectively, in male and female worms. Relative concentration of each isoenzyme diverged between male and female worms. Mammal muscle LDH-M4 type moved between LDH2 and LDH3 from female worms, and between LDH1 and LDH2 from male worms. Mammal heart H4 type enzyme was very different in electrophoretic mobility. The ratio of each isoenzyme was determined by densitometry. The major isoenzymes from female worms will be studied as a biochemical target for chemotherapeutic attack.