Effects of Rivastigmine on Behavioral Tests for Passive Training in Rats with Abdominal Hypertension

Intra-abdominal hypertension may increase brain venous pressure, which may lead to brain injury. Elevated intracranial pressure causes encephalopathy and the risk of neuronal damage due to the sharp decrease in cerebral perfusion pressure. Increased intra-abdominal pressure (IIAP) modulates brain perfusion, induces hypoxic changes and impairs memory and other cognitive functions. Rivastigmine, last introduced in clinical practice cholinesterase inhibitor, is a second generation carbamate-based, reversible, noncompetitive inhibitor of acethylcholinesterase and buthyrilcholinesterase, used for treatment of mild to moderate Alzheimer’s disease. The aim was to investigate whether artificially IIAP in rats lowers their cognitive potential and Rivastigmine is able to diminish this disturbance using passive avoidance tests. Three groups of male Wistar rats were used: 1 st saline 0.1ml/100g body weight; 2 nd IIAP to 25mmHg; 3 rd IIAP + Rivastigmine 1 mg/kg. Step-through and step-down passive avoidance tests were performed in originally made apparatus by Ugo Basile, Italy. In both tests was observed the latency of reactions – for the step-through time spend in the light chamber (178 seconds) and for the step-down time spend on the resting platform (60 seconds) of the apparatus. The rats with IIAP showed the latency of reaction similar than control group in both tests. In step-through test the group with model of IIAP and rivastigmine increased the latency of reaction on learning and long memory retention. In step-down tests the same group increased the latency only in long memory retention. It can be concluded that rivastigmine improves long term memory in rats with intra-abdominal and subsequent cerebral hypoxia.