The Glaucomatous Optic Neuroprotection Of Heat Shock Protein 70

Objective: Glaucoma is a kind of irreversible eye disease which can cause blindness. At the present time, the main clinical treatment is to decrease the intraocular pressure (IOP). But many patients'damage of optic function keep developing even their IOP has been controlled. Therefore glaucomatous optic neuroprotection treatment becomes a hot spot. Heat shock protein is a series of proteins which are brought out when the cells are stimulated. They are highly conservative in constitution. They take an important role in the growth and evolvement of life-form and HSP70 have a most important neuroprotection action. In this experiment, IOP was raised by electrocoagulating 3 episcleral and limbal veins. Then we observed the optic neuroprection of HSP70 after 4 weeks.Method: 60 SD rats were randomly divided into three groups: A: normal controlled group, B: ocular hypertension group and C: ocular hypertension after thermotolerance group. B group was anaesthetized by intraperitoneal injected 10% chloral hydrate. Then we electrocoagulated 3 episcleral and limbal veins to improve their IOP. C group was deposited in 45℃constant temperature water box 15 min after they were anaesthetized. Then they were treated with the same method as B group after 6 hours. They were given constant temperature water bath every two days. A group was bastardly operated. We observed the IOP of the three groups every two days and killed them after 4 weeks. RGCs apoptosis was observed with transmission electron microscope and immunohistochemical method was used to detect the expression of HSP70.Resultes:⑴The IOP of the three groups have no significant difference before operation. The mean value of B and C groups'IOP were52.46±1.74mmHg and 51.89±2.15mmHg at the moment when the operation was finished and their IOP became stable after a week. The IOP value was significantly different between A and B, A and C (P<0.01). there was no significant difference between B and C.⑵4 weeks later, the retinal construction became thinner and the papillary excavation became deepen.⑶Observed with transmission electron microscope, we found RGCs apotosis in B group after 4 weeks.⑷The expression of HSP70 was significantly different between A and C, B and C, A and B.Conclusions: It can raise the IOP of rats to electrocoagulat 3 episcleral and limbal veins, and the high IOP could keep a certain time. The expression of HSP70 was significantly increased after thermotolerance and HSP70 possibly take an important role in glaucomatous optic neuroprotection.