Uric acid and central nervous system functioning (a literature review)

Abstract

The high level of uric acid in blood distinguishes humans from other studied species of mammals. The reason behind this is the absence of the enzyme uricase, which is evolutionary determined. Today, hyperuricemia can be considered as a factor of “diseases of civilization.” However, uric acid can also have positive effects, because it intensifies cognitive processes. The high level of uric acid in blood probably facilitated the emergence of intellectually advanced primates. Later, it enhanced the human’s motivation for active work. In the present review, these points are substantiated using data by V.P. Efroimson on the role of hyperuricemia and gout in the development of genius, V.S. Rotenberg’s Search Activity Concept, and the R. Johnson’s hypothesis on the role of uric acid as a messenger when it is necessary to change the behavioral responses of animals upon transition to active feeding. The nonspecific activating role of hyperuricemia is the factor that links all three hypotheses together. In addition, the enhancement of cognitive functions and motivations in hyperuricemia has been confirmed in different population samples. The biochemical basis for such effects is the potential for uric acid synthesis in the central nervous system and the penetration of the blood-brain barrier by its precursors, the interrelations between the metabolism of uric acid in the central nervous system and the metabolism of catecholamines and dopamine, and the neuroprotective and antioxidative properties of uric acid.