Activity and Expression of Glutamate Oxaloacetate Transaminase during the Reproductive Cycle of a Fresh Water Fish Labeo rohita

Abstract

The activities of glutamate oxaloacetate transaminase (GOT) were measured spectrophotometrically from five tissues (liver, heart, kidney, brain, and ovary) of a non air-breathing, herbivorous fresh water fish Labeo rohita. The activities were measured separately for cytosolic (c-) GOT and mitochondrial (m-) GOT. For all tissues examined, the maximum activities were observed in the spawning phase, followed by the pre- and post-spawning phases for both c- and m-GOTs. The native agarose gel electrophoretic pattern revealed two GOT forms of different charges throughout the pre- to post-spawning phases. However, the spawning phase was marked by the expression of an additional anionic form of GOT in all tissues studied. These results indicate a distinct utilization of aspartate particularly in the spawning phase in fish via transamination reactions.