烫伤对大鼠下丘脑视上核内皮素-1基因转录和蛋白含量的影响

Effect of scald on gene transcription and content of endothelin-1 in supraoptic nucleus of rat hypothalamus

用原位杂交和免疫组织化学方法观察了烫伤后下丘脑视上核 (SON)内皮素 1(ET 1)基因转录和蛋白含量的变化 ,并用通用图像颗粒分析法估计ET 1mRNA阳性杂交信号的强度和ET 1样免疫反应物 (ET 1 ir)的免疫反应强度。与对照组相比 ,烫伤后 15min ,SON神经元胞浆内ET 1mRNA阳性杂交信号未见明显变化 ;而在烫伤后 6 0和 180min ,ET 1mRNA阳性杂交信号强度分别较比照组增加 35 1% (P <0 0 5 )和 6 2 4% (P <0 0 1)。在烫伤后 15min ,SON神经元胞浆内ET 1 ir明显减少 ,仅为对照组的 8 5 % ,显著低于对照组 (P <0 0 1)。烫伤后 6 0和180min免疫反应物强度较烫伤后 15min有所回升 ,分别为对照组的 31 5 %和 5 2 4% ,但仍显著低于对照组 (P <0 0 1)。用Northern法检测烫伤后下丘脑ET 1mRNA含量和长度变化。结果显示 ,在烫伤后 15min ,ET 1mRNA含量变化不显著 ,在烫伤后 6 0min显著增多 (P <0 0 5 ) ,在烫伤后 180min继续增至对照组 2 5倍 ,但ET 1mRNA长度在烫伤前后并无改变。以上结果表明 ,烫伤后大鼠下丘脑SONET 1mRNA含量增加 ,而ET 1 ir含量在烫伤后180min内维持在低水平。鉴于SON具有神经内分泌作用 ,烫伤后SON内ET 1mRNA和ET 1 ir的变化提示 ,ET 1在烫伤后的病理生理变化中可能有重要的神经内分泌作?

Endothelin 1 (ET 1) gene transcription and endothelin 1 immunoreactivity (ET 1 ir) in the supraoptic nucleus (SON) of rat hypothalamus were respectively observed by in situ hybridization and immunohistochemistry after scald. Intensity of ET 1 mRNA and endothelin 1 immunoreactivity (ET 1 ir) was quantified by image analysis. Compared with the control (sham scald) group, no significant change in the intensity of ET 1 mRNA positive hybridization signals in SON was found 15 min post scald, while there was a 35 1% increase in the positive hybridization signal intensity 60 min post scald ( P <0 05) and a 62 4% increase 180 min post scald ( P <0 01). The content of ET 1 ir in SON decreased significantly to 8 5% of the control 15 min post scald ( P <0 01), and gradually recovered to 31 5% and 52 4% of the control 60 min and 180 min post scald respectively, though still significantly lower than the control ( P <0 01). Pre and post scald ET 1 gene transcription in rat hypothalamus was also measured by Northern blot hybridization. No significant difference in the quantity of ET 1 mRNA was found between 15 min post scald data and those of the control. The quantity increased to a significantly higher level 60 min post scald ( P <0 05) and further in creased to 2 5 fold of the control 180 min post scald ( P <0 05). In addition, the Northern blot hybridiza tion showed that the post scald size of ET 1 mRNA remained unchanged despite of the increase in quantity. In view of the neuroendocrine role of SON, the changes in ET 1 mRNA and ET 1 ir in SON resulting from scald suggest that ET 1 may play an important role in neuroendocrine reactions following scald.[WT5HZ]