ABSTRACT
Objective To observe the effects of A2a adenosine receptor antagonist SCH442416 and ZM241385 on the expression of glutamine synthetase(GS) and L-Glutamate/L-Aspartate Transporter(GLAST) in rat retina under chronic ocular hypertension model.Methods Rat chronic ocular hypertension models were induced in the right eye of 12 male Sprague Dawley rats by blocking three episcleral veins,the left eye as control one.Intraocular pressure (IOP) was measured and compared at postoperative 1 week,2 weeks and 3 weeks.54 male chronic ocular hypertension rats were divided into 3 groups randomly,topically applying A2a adenosine receptor antagonist SCH442416,ZM241385 and carrier,respectively,three times a day for three weeks.At three weeks,mRNA and protein expression of GS and GLAST in rat retina were analyzed by RealTime-PCR and Western-blot.Results The average IOP of the modeling eyes at postoperative 1 week,2 weeks and 3 weeks were higher than that of the control eyes (all P ＜ 0.05).The mRNA and protein expression of GS and GLAST in the retina of SCH442416 and ZM241385 groups increased significantly compared to the carrier group (all P ＜ 0.05).However,the differences of mRNA and protein expression of GS and GLAST between SCH442416 and ZM241385 groups was not significant(all P ＞ 0.05).Conclusion Rat chronic ocular hypertension model can be induced by blocking three episceral veins successfully and effectively.A2a adenosine receptor antagonist SCH442416 and ZM241385 increase the expression of GS and GLAST.There seems no difference between the effects of these two drugs.
ABSTRACT
Microglia, the main innate immune cells in the central nervous system, takes part in lots of physiological and pathological processes in the brain.It not only maintains brain homeostasis but also participates in the process of brain injury and repair under pathological conditions.In developmental brain, microglial synaptic pruning may eliminate weaker synapses and retain stronger synapses.Synaptic pruning also plays a vital role in mediating the formation of neural circuit under physiological condition, contributes to cell and myelin debris clearance, promotes maturation of oligodendrocytes, which surround the bare axon to form myelin sheath, and helps the regeneration of neurons and synapses.Recently, increasing number of studies on microglial synaptic pruning has advanced our understanding of the underlying mechanism for synaptic pruning and its relevant physiological functions.Here, we reviewed microglial synaptic pruning function and its potential regulatory mechanisms in brain under physiological and pathological conditions.