Tetrahydroaminoacridine affects the cholinergic function of blood-brain barrier.

In rat brain microvessels, tetrahydroaminoacridine (THA) caused a significant inhibition of both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities, in a dose-dependent manner. THA resulted to be a more potent inhibitor of BuChE than AChE. Lineweaver-Burk plots showed that Km (app) and V were altered by THA, indicating mixed competitive/non-competitive inhibition. The results of the present study also established that the three molecular forms of BuChE (G1, G2 and G4), recently described to be present in brain microvessels, are inhibited after THA treatment.