Enzymatic histochemistry of retina with experimental intraocular pressure elevation in rabbits

To investigate the pathogenesis of retina lesions caused by intraocular pressure elevation, activities and distribution of enzymes in retina including lactic dehydrogenase (LDH), succinate dehydrogenase (SDH), adenosinetriphosphatase (AT-Pase), acid phosphatase (ACP), cholinesterase (ChE), cytochrome oxidase (CCO), nucleotidase (5'-Nase) and glucose-6-phosphatase (G6Pase) were determined histochemically in 30 rabbits. It was found that 1) in the early stage of intraocular pressure elevation, the activities of LDH, SDH, ATPase, ACP, and ChE in retina were increased, while the activities of CCO, 5'-Nase decreased; 2) in the late stage of intraocular pressure elevation, the activities of all these enzymes but ACP, which showed a reduced activity, were close to the normal level; 3) in superoxide dismutase.(SOD-CCE) treated group, except the slight increase of LDH and G6Pase activities, the activities of the remaining enzymes were near to normal. Our results suggest that the various histochemical changes in retina induced by intraocular pressure elevation were compensatory in the early stage and were beneficial to the supply of energy needed in retinal tissue and cellular metabolism; while in the late stage, the lesion of retina cells developed due to decompensation. SOD-CCE could alleviate the retinal lesions caused by intraocular pressure elevation, and can be used as auxiliary drug for the treatment of intraocular pressure elevation.