Identification of Phosphoethanolamine and Phosphoserine in the Brain of the Pond Fish Perccottus Glehni (Eleotridae, Perciformes, Dyb. 1877)

Abstract

Significant modifications to the free amino acid pool and various other compounds in the bodies of poikilotherms in response to decreased temperature reflect significant alterations in their mechanisms of adaptation. The literature lacks data on the contributions of such free compounds to the low-temperature adaptation of the brains of poikilotherms. Our previous studies showed that acute cold shock induced the appearance of large quantities of two ninhydrin-positive compounds of unknown nature in the brain of the eurythermal pond fish Amur sleeper. The experiments reported here show that the brain accumulates these compounds by the beginning of the winter period. They were found to be the phospholipid metabolites phosphoethanolamine and phosphoserine. The winter phosphoethanolamine pool was 94 times greater than the summer level, while phosphoserine was present only in summer. It is suggested that accumulation of phosphoethanolamine and phosphoserine is associated with adaptive modifications of membrane phospholipids at low temperatures.