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。方法通过给予大鼠饮用3%氯化钠的方法制作高渗刺激模型,并用WGA-HRP逆行追踪、抗Fos、抗酪氨酸羟化酶(TH)或加压素(VP)及胶质纤维酸性蛋白(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。星形胶质细胞(AST)紧密包绕在神经元周围形成神经元-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。

Study on hyperosmotic regulation-involved reciprocal pathways between medullary visceral zone and hypothalamic paraventricular nucleus or supraoptic nucleus

Objective To test the possibility of reciprocal pathways between medullary visceral zone (MVZ) and hypothalamic paraventricular nucleus (PVN) or supraoptic nucleus (SON) following hyperosmotic stimulation. Methods Hyperosmotic pressure animal model was established by administering 3% sodium chloride as drinking water to rats. 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 quadruple 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 increased markedly. There were also a large number of 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 reactivities took on hypertrophic cell bodies, thicker and longer processes. Quadruplicate immunohistochemical staining showed that a neuron could be closely surrounded by many AST and they formed neuron-astrocytic complex (N-ASC). Conclusion The neurons and AST might be very active following hyperosmotic pressure and N-ASC as a functional unit might serve to modulate the osmotic pressure. There was reciprocal osmoregulation pathways between the MVZ and SON or PVN in the brain.