大鼠延髓内脏带与下丘脑室旁核、视上核往返投射通路参与高渗调节反应的研究

目的：探讨延髓内脏带(MVZ)与下丘脑室旁核(PVN)和视上核(SON)之间是否存在往返渗透压投射通路。方法：采用给大鼠饮用3％氯化钠的方法复制高渗刺激模型，并用WGA-HRP逆行追踪、抗Fos和抗酪氨酸羟化酶(TH)或加压素(VP)及胶质原纤维酸性蛋白(GFAP)免疫组织化学相结合的四重标记方法，观察MVZ、PVN和SON中WGA-HRP、Fos、TH、VP和GFAP的阳性分布及表达状况。结果：高渗刺激后MVZ、PVN和SON内Fos阳性细胞明显增多。GFAP阳性结构也明显增多，其分布与Fos阳性细胞分布基本一致，表现为胞体肥大、突起粗长。AST紧密包绕在神经元周围形成神经元-星形胶质细胞(AST)复合体(N-ASC)。结论：神经元和AST以N-ASC的形式共同参与渗透压调节反应，体内存在MVZ和SON或PVN之间往返的渗透压调节通路。

RECIPROCAL PATHWAYS BETWEEN MEDULLARY VISCERAL ZONE AND HYPOTHALAMIC PARAVENTRICULAR NUCLEUS OR SUPRAOPTIC NUCLEUS INVOLVED IN HYPEROSMOTIC REGULATION

Objective To elucidate the existence of reciprocal pathways between medullary visceral zone (MVZ) and hypothalamic paraventricular nucleus (PVN) or supraoptic nucleus(SON) following hyperosmotic stimulation. Methods Hyperosmosis was produced in rats by drinking 3% sodium chloride solution. The distributions and expressions of HRP retrogradely labeled neurons, Fos, tyrosine hydroxylase (TH) or vasopressin (VP) positive neuron and glial fibrillary acidic protein (GFAP) positive astrocytes(AST) in MVZ, SON and PVN were observed by quadruplicate labeling methods of WGA HRP retrograde tracing combined with anti Fos, TH (or VP) and GFAP immunohistochemical technique. Results Fos positive neurons within the MVZ, PVN and SON were increased markedly. There was also a marlced increase in GFAP positive structures in the brain, and their distribution pattern was fundamentally similar or analogous to Fos positive neurons in the above mentioned areas. The augmented GFAP structures manifested as hypertrophic cell bodies, with thicker and longer processes. Quadruplicate immunohistochemical staining showed that neurons were surrounded by many AST to form neuron astrocytic complex (N ASC). Conclusion The neurons and AST, as a functional unif in the form of N ASC, might actively participate in modulating osmotic pressure. There was reciprocal osmoregulation pathways between the MVZ and SON or PVN in the brain