Dehydration induces Fos, but not increased vasopressin mRNA in the supraoptic nucleus of aged rats.
Dehydration induces Fos, but not increased vasopressin mRNA in the supraoptic nucleus of aged rats.
复制标题
脱水会诱导老年大鼠视上核中的 Fos，但不会增加加压素 mRNA。
DOI：
10.1016/0006-8993(94)90229-1
复制
发表时间：
1994
期刊：
影响因子：
2.9
通讯作者：
Olschowka,JA
中科院分区：
文献类型：
--
作者：
Sladek,CD;Olschowka,JA
脱水诱导Fos表达，增加下丘脑视上核（SON）和室旁核（PVN）抗压素（VP） mRNA聚a尾的长度和VP mRNA的含量。目前的研究是为了评估衰老对这些反应的影响。4、14和28-30月龄的Fischer 344大鼠被剥夺水72小时或允许自由取水。通过免疫细胞化学检测Fos在SON和PVN中的诱导作用，以提供细胞活化的指标。用Northern分析法检测SON中VP mRNA的含量和大小，作为VP合成能力的指标。脱水诱导三个年龄的大鼠渗透压升高，但血清VP仅在4月龄和14月龄大鼠中升高。4月龄和14月龄脱水大鼠血清VP升高，同时垂体后叶VP含量降低。脱水和脱水老龄大鼠PP VP含量均较其他年龄大鼠降低（P = 0.0007）。所有缺水大鼠的SON和PVN均诱导Fos，而不考虑年龄。脱水后两个细胞核Fos染色密度增加（SON,P = 0.002； PVN,P = 0.0001）。脱水动物双核表达Fos的细胞数量也显著增加（SON,P = 0.0022； PVN,P = 0.0056）。年龄对Fos染色密度无显著影响。相比之下，脱水并没有引起老龄脱水大鼠SON中VP mRNA大小和含量的预期增加，但在4月龄和14月龄大鼠中这两个参数都有所增加（P<0.05）。因此，老年Fischer大鼠在慢性脱水期间不能增加血清VP并不是由于神经元激活减少（如Fos诱导所示），而是由于不能增加可用于翻译的VP mRNA的数量而导致VP的PP储存减少。
Dehydration induces Fos expression and increases the length of the vasopressin (VP) mRNA poly-A tail and the content of Vp mRNA in the supraoptic (SON) and paraventricular nuclei (PVN) of the hypothalamus. The current studies were performed to evaluate the effect of aging on these responses. Fischer 344 rats of 4, 14, and 28–30 months of age were either water deprived for 72 h or allowed ad libitum access to water. Fos induction in the SON and PVN was examined by immunocytochemistry in order to provide an index of cellular activation. VP mRNA content and size was examined in SON by Northern analysis as an index of VP synthetic capacity. Dehydration induced the expected increase osmolality in all three ages, however, serum VP was only increased in the 4- and 14-month-old rats. The increase in serum VP was accompanied by a decrease in VP content of the posterior pituitary (PP) in the dehydrated 4- and 14-month-old rats. PP VP content was reduced in both the hydrated and dehydrated old rats relative to the other ages (P = 0.0007). Fos was induced in both SON and PVN of all water deprived rats regardless of age. The density of Fos staining was increased in both nuclei following dehydration (SON,P = 0.002; PVN,P = 0.0001). There was also a significant increase in the number of cells expressing Fos in both nuclei in the dehydrated animals (SON,P = 0.0022; PVN,P = 0.0056). There was no significant effect of age on the density of Fos staining. In contrast, dehydration failed to elicit the expected increase in VP mRNA size and content in the SON of the aged dehydrated rats although both of these parameters were increased in the 4- a and 14-month-old rats (P<0.05). Thus, the inability of old Fischer rats to increase serum VP during chronic dehydration is not caused by decreased activation of the neurons (as indicated by Fos induction), but apparently reflects depletion of PP stores of VP due to an inability to increase the amount of VP mRNA available for translation.