CELLULAR-LOCALIZATION OF PROGLUCAGON GLUCAGONLIKE PEPTIDE-I MESSENGER-RNAS IN RAT-BRAIN
CELLULAR-LOCALIZATION OF PROGLUCAGON GLUCAGONLIKE PEPTIDE-I MESSENGER-RNAS IN RAT-BRAIN
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DOI：
10.1002/jnr.490160110
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发表时间：
1986-01-01
影响因子：
4.2
通讯作者：
LUND, PK
中科院分区：
文献类型：
--
作者：
HAN, VKM;HYNES, MA;LUND, PK
应用原位杂交组织化学、北方印迹杂交和免疫细胞化学技术研究了大鼠脑内胰高血糖素样免疫反应物（GLI）的生物合成。成年大鼠脑延髓孤束核中的细胞与对应于胰高血糖素原mRNA编码胰高血糖素样肽I（GLP-I）的核苷酸序列的合成寡核苷酸探针（GLP-I寡聚体）杂交，并用对胰高血糖素原、胰高血糖素和GLP-I的两个抗原决定簇具有特异性的抗血清染色。这些数据表明，在孤束核的细胞中，通过类似于胰腺中产生的胰高血糖素原mRNA的表达，存在胰高血糖素原的从头合成。先前的研究表明，下丘脑中的细胞被GLP-1抗血清染色，但不被胰高血糖素抗血清染色。然而，下丘脑中的细胞不与GLP-1寡聚体杂交，因此可能产生GLP-1免疫反应物，该免疫反应物由与胰腺胰高血糖素原mRNA编码胰高血糖素和GLP-1不同的mRNA编码。北方印迹杂交的cDNA探针编码整个胰腺胰高血糖素原序列没有检测到胰高血糖素原/GLP-Ⅰ mRNA的多聚腺苷酸化RNA（聚A RNA）从成年大鼠脑干和下丘脑，可能是因为他们的丰度低。然而，来自胎鼠脑的Poly A RNA含有两种与胰高血糖素原cDNA探针杂交的mRNA。一个1,300个碱基的mRNA与胰腺胰高血糖素原mRNA大小相同。第二个1,500个碱基的mRNA可能编码成年大鼠下丘脑中检测到的GLP-1免疫反应物。孤束核中存在胰高血糖素和胰高血糖素样肽的神经元表明这些肽在味觉和/或心肺控制中的作用。
Techniques of in situ hybridization histochemistry, Northern blot hybridization, and immunocytochemistry were used to investigate the biosynthesis of glucagon-like immunoreactants (GLIs) in rat brain. Cells in the nucleus tractus solitarius of the medulla oblongata of adult rat brain hybridized to a synthetic oligonucleotide probe (GLP-I oligomer) corresponding to nucleotide sequences in pancreatic proglucagon mRNA encoding glucagon-like peptide I (GLP-I), and stained with antisera specific for two antigenic determinants of pancreatic proglucagon, glucagon, and GLP-I. These data suggest that there is de novo synthesis of proglucagon in cells of the nucleus tractus solitarius via expression of a proglucagon mRNA similar to that produced in pancreas. Previous studies have shown that cells in hypothalamus stain with GLP-I antisera, but not with glucagon antisera. However, cells in the hypothalamus did not hybridize with the GLP-I oligomer and may therefore produce a GLP-I immunoreactant that is encoded by a mRNA different from the pancreatic proglucagon-mRNA-encoding glucagon and GLP-I. Northern blot hybridizations with a cDNA probe encoding the entire pancreatic proglucagon sequence did not detect proglucagon/GLP-I mRNAs in polyadenylated RNAs (Poly A RNA) from adult rat brainstem and hypothalamus, probably because of their low abundance. Poly A RNAs from fetal rat brain, however, contained two mRNAs that hybridized to the proglucagon cDNA probe. One mRNA of 1,300 bases is the same size as pancreatic proglucagon mRNA. The second mRNA of 1,500 bases may encode the GLP-I immunoreactant detected in the hypothalamus of adult rat brain. The presence of neurons with glucagon and glucagon-like peptides in the nucleus tractus solitarius suggests a role of these peptides in gustatory and/or cardiopulmonary control.