Abstract
The maximum rates of adenosine triphosphatase (ATPase) systems related to energy consumption were systematically evaluated in synaptic plasma membranes isolated from the striata of male Wistar rats aged 2, 6, 12, 18, and 24 months, because of their key role in presynaptic nerve ending homeostasis. The following enzyme activities were evaluated: sodium-potassium-magnesium adenosine triphosphatase (Na(+), K(+), Mg(2+)-ATPase); ouabain-insensitive magnesium adenosine triphosphatase (Mg(2+)-ATPase); sodium-potassium adenosine triphosphatase (Na(+), K(+)-ATPase); direct magnesium adenosine triphosphatase (Mg(2+)-ATPase); calcium-magnesium adenosine triphosphatase (Ca(2+), Mg(2+)-ATPase); and acetylcholinesterase. The results showed that Na(+), K(+)-ATPase decreased at 18 and 24 months, Ca(2+), Mg(2+)-ATPase and acetylcholinesterase decreased from 6 months, while Mg(2+)-ATPase was unmodified. Therefore, ATPases vary independently during aging, suggesting that the ATPase enzyme systems are of neuropathological and pharmacological importance. This could be considered as an experimental model to study regeneration processes, because of the age-dependent modifications of specific synaptic plasma membranes. ATPases cause selective changes in some cerebral functions, especially bioenergetic systems. This could be of physiopathological significance, particularly in many central nervous system diseases, where, during regenerative processes, energy availability is essential.