ABSTRACT
Aim To explore the effect of Neu-P11,a novel melatonin agonist with similar function of melatonin,on IOP of acute high IOP animals and the related mechanism.Methods The experiment used the Trendelenburg position(head low feet high position of 80°)to establish acute high IOP model.Rats were placed in the Trendelenburg position and used Tonopen XL contact tonometer to measure IOP(every 5 minutes measured once IOP,and the maximum value in 20 minutes)in 8 :00～9 :00 am.And then,thirty Sprague-Dawley rats(8 week-old)were divided into five groups: normal IOP+normal saline,high IOP+normal saline,high IOP+10 mg·kg-1 Mel,high IOP+20 mg·kg-1 Neu-P11,high IOP+50 mg·kg-1 Neu-P11.Put in a flat to rest 2 h,animals were placed in Trendelenburg position again and then,IOP was measured every hour in the flat by 6 hours.After excessive sodium pentobarbital administration continuous for 1 week,the serum was collected and stored for subsequent detection at the end of the experiment.The level of MDA,SOD and GSH-Px enzyme activity of the rat serum was tested by kit accordingly.HE staining method was used to identify the SD rat retinal morphological changes.Results Trendelenburg position could induce IOP of model group rats,which was increased by 202.9％(P<0.01)and the content of MDA,reduced the activity of SOD and GSH-Px enzyme,retinal thickening was observed and its level was not clear.Neu-P11/Mel could significantly improve oxidative stress level and retinal edema in rats.Conclusion Neu-P11 could reduce IOP of the acute high IOP animals,which might be involved in the lower level of oxidative stress in the body.
ABSTRACT
Objective To explore the effects of the new melatonin nonselective agonists Neu-P11 on intraocular pressure (IOP) and glial fibrillary acid protein (GFAP) expression in the retina of acute high IOP rat.Methods Twenty-four male Sprague-Dawley rats were randomly divided into 4 groups (6 cases in each group):Normal IOP with local treatment (NIL) group,high IOP with local treatment (HIL) group,HILwith melatonin treatment (HIL-M) group,HIL with Neu-P11 treatment (HIL-N) group.10 μL normal saline was instilled in NIL group and HIL group,while 10 μL 100 μmol · L-1 Mel/Neu-P11 treated in HIL-M group and HIL-N group.After 2 hours of rest,rats were placed in the Trendelenburg position duration 45 minutes.And then,IOP was measured every hour for 6 hours,and repeated it for a week.The excessive sodium pentobarbital was injected to SD rats at the end of the experiment.The rat eyeballs were took out to perform HE and immunohistochemical staining to detect retina GFAP protein expression.Results After a week,IOP in HIL group was (41.26 ± 1.73) mmHg (1 kPa =7.5 mmHg),NIL group was (13.61 ± 0.55) mmHg,which mean the Trendelenburg could induce high IOP in SD rats.Compared with the NIL group,the retinal becoming thick,the level of organization was not clear and the expression of GFAP protein was quite high in HIL group.At the same time,the GFAP protein expression and IOP were significantly weakened in HIL-M group and HIL-N group compared with HIL group.Conclusion Neu-P1 1 can reduce IOP,inhibit the activation of gliocyte,and decrease the expression of GFAP to protect the retina.