内源性过氧化物酶在大白鼠脑内的分布

THE MAIN DISTRIBUTION OF ENDOGENOUS PEROXIDASE IN THE RAT BRAIN

为了鉴别内、外源性过氧化物酶的分布情况,本文应用光学及暗视野显微镜观察了大白鼠延、桥、中脑、丘脑、下丘脑、海马及纹状体等部。观察到了Ⅲ、Ⅳ脑室、中脑导水管周围灰质表面都含大量棕褐色过氧化物酶颗粒呈非神经元性分布。在蓝斑全部或背侧部,小脑腹侧部,海马背侧部都可以见HRP颗粒。在韁内侧核、纹状体,下丘脑视上核、交叉上核等可见到少量HRP颗粒。在弓状核内也有大量阳性反应颗粒:有一些分布于多突神经元内;但大部分呈非神经元性分布。尾壳核及膈外侧核背部仅有少量颗粒。在穹隆连合,胼胝体内的颗粒都沿着神经纤维束分布。穹隆下器含有大量颗粒,尤其是其背侧部。这些酶的分布似乎与这些核团的神经分泌、神经递质的合成、代谢及释放密切有关。而其中某些作用有可能是通过脑脊液来完成的。

Horseradish peroxidase(HRP)has been curently used for tracing the interrelationship between neurons in peripheral and central nervnos system.In order to differentiate endo-and exogenous peroxidases,15 adult,healthy rats were selected for investigating the distribution of endogenous peroxidase in tissues.Fresh cryostat frozen sections of brain were fixed in fixatives of various concentrations and PH,and sections were made after perfusion of the fixative through heart.They were incubated in media containing DAB and hydrogenperoxide.Potassium cynide or sodium azide was used as inhibitators.The reaction of peroxidase in medula oblongata,pons,midbrain,thalamus,hypothamus,hippocampus and striatum etc were studied with dark field and transmitted light microscope.In the superficial layer of theⅢandⅣventricles and periaqueductal gray substance of midbrain,there were large number of dark brown peroxidase granules with non neuronal distribution.The peroxidase granules were found in the entire or the dorasal part of locus ceruleus,the ventral part of cerebellum and the dorasal part of hippocampus.Small amount of granules were located in medial nucleus of habenularis,stria medullaris,nucleus supraopticus hypothalami and suprachiasmaticus.Large amount of positive reactive granules were found in nucleus arcuate.Some of them were localized in the perineurons of polydendritic neurons but most of them were of nonneuronal distribution.Sparse granules were also observed in the dorsomedial part of nucleus caudatus putamen and dorsal part of nucleus septicus lateralis.In commisure fornix and corpus callosum,the granules were distributed along the nerve fiber bundle.There were large amount of positive reactive granules around the subfornix organ especially on its dorsal part.To sum up,the main distribution of them are periventricular,periaqueductal gray substance and periventricular organs(such as area postrema,locus coeruleus,nucleus arcuata,subfonix organ and several neurosecretory nuclei of hypothalamus).It seems that the distribution of this enzymes might be closely related to synthesis,metabolism and release of the neurosecretion or transmitters of these nuclei and some of them might act through the cerebro-spinal fluid.