Lactic and malic dehydrogenases and their multiple molecular forms in the mongolian gerbil as compared with the rat, mouse and rabbit

Abstract

1.1. Lactic dehydrogenase (LDH) and malic dehydrogenase (MDH), have been studied in the major organs and blood serum of the mongolian gerbil, Meriones unguiculatus, and comparisons made with the laboratory rat, mouse and rabbit.2.2. Total enzyme activities, especially those of LDH, are lower for Meriones than for the rat and the mouse, indicating that the common metabolism of Meriones may deviate from that of other rodents.3.3. The content of B subunits in the LDH isozyme pattern of Meriones [expressed with formulae for isozyme indices (IEI), and isozyme patterns (IEP)] is lower than for the other species. There is no correlation between LDH/MDH quotients and IEI or IEP values. Thus, this material affords no proof that a dominance of A subunits is preferred in tissues with anaerobic metabolism.4.4. In the liver of Meriones, LDH 5 is totally dominant, a rare situation for a mammal. The isozyme pattern of the kidney of Meriones is similar to that of the rat and the mouse in spite of the fact that Meriones demonstrates a pronounced capacity for water conservation.5.5. The isozyme patterns and the enzyme levels of the various organs of the species are reflected in their blood sera. Only one MDH fraction is recognizable in serum from the rat, mouse and rabbit.