Kidd E J, Grahames C B, Simon J, Michel A D, Barnard E A, Humphrey P P
Glaxo Institute of Applied Pharmacology, Department of Pharmacology, University of Cambridge, UK.
Mol Pharmacol. 1995 Oct;48(4):569-73.
We used transcript-specific oligonucleotides to examine the localization in the rat nervous system of the corresponding mRNAs for the two P2X purinoceptor genes cloned recently from the rat vas deferens and PC12 cells. PC12 P2X purinoceptor mRNA was labeled in the olfactory tubercle, striatum, hypothalamus, hippocampus, dentate gyrus, amygdala, cortex, and cerebellum, whereas the vas deferens P2X purinoceptor-specific probes labeled the cerebellum and, at lower levels of expression, the striatum, hippocampus, and cortex. Both types of P2X purinoceptor transcript were found on cell bodies in the nodose and superior cervical ganglia. The presence of these two purinoceptor transcripts in the brain was confirmed by polymerase chain reaction. Two partial cDNAs, identical to sections of the PC12 or vas deferens P2X purinoceptor coding sequences, were amplified from neonatal brain and cerebellum poly(A)+ RNA, respectively. These findings are in broad agreement with earlier Northern blot studies on the PC12 P2X purinoceptor mRNA but differ from those for the vas deferens P2X purinoceptor mRNA, which had not previously been detected in adult brain. This difference is attributed to the low levels seen in the adult compared with the neonate and to the greater sensitivity of the methods used in the present study. The neonate medial habenula had low levels of transcripts for the PC12 but none for the vas deferens P2X purinoceptor. Because pharmacologically the recombinant PC12 P2X purinoceptor differs from the functional purinoceptor in the medial habenula, these results suggest the existence of other, unidentified, P2X purinoceptors in the rat nervous system.
我们使用转录本特异性寡核苷酸来检测最近从大鼠输精管和PC12细胞中克隆的两个P2X嘌呤受体基因相应mRNA在大鼠神经系统中的定位。PC12 P2X嘌呤受体mRNA在嗅结节、纹状体、下丘脑、海马体、齿状回、杏仁核、皮层和小脑中被标记，而输精管P2X嘌呤受体特异性探针标记了小脑，并且在较低表达水平下标记了纹状体、海马体和皮层。两种类型的P2X嘌呤受体转录本都在结状神经节和颈上神经节的细胞体上被发现。通过聚合酶链反应证实了这两种嘌呤受体转录本在脑中的存在。分别从新生脑和小脑的聚腺苷酸加尾RNA中扩增出两个与PC12或输精管P2X嘌呤受体编码序列部分相同的部分cDNA。这些发现与早期关于PC12 P2X嘌呤受体mRNA的Northern印迹研究大致一致，但与输精管P2X嘌呤受体mRNA的研究结果不同，后者此前在成体脑中未被检测到。这种差异归因于与新生儿相比成体中所见的低水平以及本研究中所用方法更高的灵敏度。新生内侧缰核中PC12的转录本水平较低，但输精管P2X嘌呤受体的转录本则没有。由于重组PC12 P2X嘌呤受体在药理学上与内侧缰核中的功能性嘌呤受体不同，这些结果表明大鼠神经系统中存在其他未鉴定的P2X嘌呤受体。
