Simonet L, St Lezin E, Kurtz T W
Department of Laboratory Medicine, University of California, San Francisco 94143-0134.
Hypertension. 1991 Nov;18(5):689-93. doi: 10.1161/01.hyp.18.5.689.
In the inbred Dahl salt-sensitive rat (SS/Jr strain), it has been proposed that a T for A transversion in the DNA sequence encoding amino acid 276 in the alpha 1 subunit isoform of Na+,K(+)-ATPase may impair ion transport and contribute to the pathogenesis of hypertension. This hypothesis is of major scientific interest because it represents the first attempt to explain the pathogenesis of salt-sensitive hypertension on the basis of a specifically defined mutation at the DNA level. We devised a polymerase chain reaction technique to screen the genomic DNA of multiple SS/Jr rats for the T for A transversion reported in the complementary DNA (cDNA) encoding the alpha 1 subunit of Na+,K(+)-ATPase. When eight Dahl SS/Jr rats from Harlan Sprague Dawley Inc. were tested with the polymerase chain reaction technique, we found no evidence of this mutation in the Na+,K(+)-ATPase gene. Direct sequence analysis of the gene in three SS/Jr rats also did not show the T for A transversion. These results 1) strongly suggest that commercially available Dahl SS/Jr rats do not carry a T for A transversion in the genomic DNA sequence encoding amino acid 276 in the alpha 1 subunit isoform of Na+,K(+)-ATPase and 2) raise the possibility that the previous finding of a mutation in the cDNA of the SS/Jr rat may have been due to a reverse transcriptase error during cDNA synthesis.
在近交系达利盐敏感大鼠（SS/Jr品系）中，有人提出，在编码Na⁺,K⁺-ATP酶α1亚基异构体中第276位氨基酸的DNA序列中，由T到A的颠换可能会损害离子转运，并导致高血压的发病机制。这一假说具有重大的科学意义，因为它是首次尝试在DNA水平上基于特定定义的突变来解释盐敏感性高血压的发病机制。我们设计了一种聚合酶链反应技术，以筛选多只SS/Jr大鼠的基因组DNA，寻找编码Na⁺,K⁺-ATP酶α1亚基的互补DNA（cDNA）中报道的由T到A的颠换。当用聚合酶链反应技术对来自哈兰·斯普拉格·道利公司的8只达利SS/Jr大鼠进行检测时，我们在Na⁺,K⁺-ATP酶基因中未发现这种突变的证据。对3只SS/Jr大鼠的该基因进行直接序列分析，也未显示由T到A的颠换。这些结果：1）强烈表明，市售的达利SS/Jr大鼠在编码Na⁺,K⁺-ATP酶α1亚基异构体中第276位氨基酸的基因组DNA序列中不携带由T到A的颠换；2）增加了先前在SS/Jr大鼠cDNA中发现突变可能是由于cDNA合成过程中逆转录酶错误的可能性。
