Varshney_2021_Neuropeptides_86_102122

Renin Angiotensin System plays significant role in the memory acquisition and consolidation apart from its hemodynamic function in the pathophysiology of Alzheimer's disease (AD). It has been reported that Ang (1-7) ameliorates the cognitive impairment in experimental animals. However, the effect of Ang (1-7)/Mas receptor signaling is yet to be explored in Abeta42-induced memory impairment. Abeta42 was intracerebroventricularly injected into the male rats on day-1 (D-1) of the experimental schedule of 14 days. All the drugs were administered from D-1 to D-14 in the study design. Abeta42 significantly increased the escape latency during Morris water maze (MWM) test on D-10 to13 in the animals. Further, Abeta42 significantly decreased the time spent and percentage of total distance travelled in the target quadrant of the rats on D-14 in the MWM test. Abeta42 also significantly decreased the spontaneous alteration behavior on D-14 during Y-maze test. Moreover, there was a significant increase in the level of Abeta42, decrease in the cholinergic function (in terms of decreased acetylcholine and activity of cholinesterase, and increased activity of acetylcholinesterase), mitochondrial function, integrity and bioenergetics, and apoptosis in all the rat brain regions. Further, Abeta42 significantly decreased the level of expression of heme oxygenase-1 in all the rat brain regions. Ang (1-7) attenuated Abeta42-induced changes in the behavioral, biochemical and molecular observations in all the selected rat brain regions. However, A779, Mas receptor blocker, significantly abolished the beneficial effects of Ang (1-7) in Abeta42-induced cognitive deficit animals. These observations clearly indicate that the Ang (1-7)/Mas receptor activation could be a potential alternative option in the management of AD.