| Background: Epilepsy is a syndrome of the brain function disorder in result of many diseases. The disorder is of seizure , abrupt and temporary induced by the abnormal hypersynchrony discharage of the neurons of the brain. The kanic acid (KA) is a structural analogue of the aminoglutaminic acid, excitatory amino acid in the brain. KA model is used generally for the study in the epilepsy. Hippocampus is one of the most sensitive areas to the ischemia. At the beginning of the last century, Scharrer had pointed out that the vulnerability of the hippocampus incriminates the style of blood supply of its. Gu Qing, et al had seen the hippocampal microangiopathy in the auditus seizure rat in the scanning electron microscope.Objective: In this study, the rat induced by KA injection was used as the animal model for Epilepsy. And the microvessels of hippocampus was showed by the alkali phosphatase method. And quantitative observation of the microvessels of hippocampus was carry out to expose the role of the angioarchitecture in the pathogenesy of the epilepsy.Methods:⑴A total of 12 healthy adult Sprague-Dawley (SD) rats, male, weighting 180-250g were used for this study. The rats were randomly divided into 2 groups: the normal (n=6) and experiment group (n=6).⑵Then the experiment rats were treated by cervical hypodermic injection of KA(10mg/kg) to built the epilepsy model. The control rats were injected NS. The seizure of KA injected rats was to up to 4 or 5 grade of the Racine's standard.⑶In the 7th day after injection, the rats were perfused through heart when they were anesthesia by Chloral Hydrate. And the brains were got, post fixed, dehydrated gradiently in the alcohol, then impregnated andembedded in the celloidin, sliced into 90μm thick. The slices with the biggest dorsal hippocampus were stained by the alkali phosphatase method, then routine mounting.⑷Observe the slices in a light microscope and analyze the microvessles quantitatively by NIS Element BR analysis system. The molecular layer of the hippocampus were measured through 5 successive high power fields (36300×90μm3) in 3 continuous slices with the biggest dorsal hippocampus. The number of microvessels, the average of the biggest of diameter and the outer-to-outer length of the microvessels were analyzed. Then the averages of these indexes and the averages of length of the microvessels were calculated.⑸The results were presented in a average±S.D.; And the data were processed by SPSS 11.5 software. P<0.05 was statistical significance.Results:⑴The microvessels of the hippocampus were arranged in layers according to the pattern of the structures of the hippocampus. This style was the most obvious CA1,CA2: the density of the microvessels in the stratum oriens was the highest, the second was the stratum pyramidalis. And the least was in the molecular layer. In the CA3, the order of the density of the microvessels was the stratum pyramidalis > the stratum oriens > the molecular layer. The arrangement of the microvessels was uniform in the three layers of CA4. In the dentate gyrus, the order of the density of the microvessels was the molecular layer > the stratum oriens > the stratum pyramidalis. The arrangement styles of the microvessels were similar between two groups.⑵The microvessels of experiment group was 5.21±0.62 in number, higher than that of the control group ( 3.56±0.76)significantly, P=0.001. The microvessels of experiment group was 4.25±0.23μm in average diameter, lower than that of the control group (5.35±1.04μm)significantly, P=0.030. The microvessels of experiment group was 828.81±82.75μm in length outer-to-outer, longer than that of the control group ( 438.12±64.23μm) significantly, P=0.000. The average length was similar between two groups.Conclusion:⑴The microvessels of the hippocampus were arranged in layers according to the pattern of the structures of the hippocampus. Seizure ratsdidn't changed it obviously.⑵The density of the microvessels in the molecular layer of the CA1 were increased significantly in 7th day after KA injection.
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