1.Protective Effects of 5-HT1A Receptor Inhibition and 5-HT2A Receptor Stimulation Against Streptozotocin-Induced Apoptosis in the Hippocampus
Siamak Shahidi ; Nasrin Hashemi-Firouzi ; Simin Afshar ; Sara Soleimani Asl ; Alireza Komaki
Malaysian Journal of Medical Sciences 2019;26(2):40-51
Introduction: Intracerebroventricular administration of streptozotocin (icv-STZ) induced
apoptosis changes in neurons similar to Alzheimer's disease. The serotonergic system via its
receptor involved in survival of neurons. The present study examined the ability of selective
5-HT1A receptor antagonist (NAD-299) and 5-HT2A receptor agonist (TCB-2) to attenuate the
apoptosis caused by the icv-STZ in the rat.
Methods: The icv-STZ (3 mg/kg, 10 μL, twice) induced neuronal loss in the hippocampus
of adult male rats. Animals were divided into naive control, sham-operated, STZ+saline (1 μL, icv),
STZ+NAD-299 (5 μg/μL, icv), STZ+TCB-2 (5 μg/μL, icv), and STZ+NAD-299+TCB-2 (5 μg/μL of any
agent, icv) groups. Following the 35 days’ treatment period, neuronal apoptosis was detected using
the Tunnel. Cells with morphological features of apoptotic cell were contended by microscopy.
Results: TCB-2 and NAD-299 administration decreased number of apoptotic neurons in
the treatment group compared with the STZ group. Combined treatment of STZ rat with NAD+TCB
more decreased number of apoptotic cells in compare to TCB-2 or NAD-299 treated STZ groups.
Conclusion: Treatment with 5-HT1A receptor antagonist or 5-HT2A receptor agonist
diminished apoptosis. The beneficial effect of 5HT1A receptor inhibition was potentiated with
activation of 5-HT2A receptor in prevention of apoptosis in hippocampus.