The variation of four amino acids release of the retina in acute ocular hypertension in rabbits / 中华眼底病杂志

ABSTRACT

Objective To monitor the release of amino acids of the whole retina during and after experimental glaucoma by increasing the intraocular pressure (IOP). Methods Experimental glaucoma was induced in one of the two eyes of rabbits by increasing IOP at 120 mm Hg for 45 min under infusion of saline in anterior chamber;then the pressure was released and the needle inserted into the anterior chamber was removed,this state was maintained for another 45 min.Every 15 min during the experiment 5 rabbits were killed and experimental eyes were enucleated.Aliquots (20 ?l) of the retinal extracts (see below) were mixed with ophthaldialdehyde reagent and analysed for amino acid content by the HPLC method of Wangwei, using a 150 mm?4.6 mm,5 ?m C18 column. Results A large increase in the release of glutamate,but not of the other three amino acids monitored,occurred during initial experimental ocular hypertension.It reached peak value of (111.73?17.46) 10 -5 mmol/g at 15 min of hypertension.15 min after release of intraocular pressure,again,immediately large and specific increase in the concentration of glutamate was reached to (102.96?51.91) 10 -5 mmol/g.In eyes subjected to paracentesis of anterior chamber,no difference was found between experimental eyes and controls. Conclusion These results suggest that glutamate is triggered by increasing the IOP,and it releases not only during the period of experimental ocular hypertension,but also afterwards.