Altered expression of G‐protein mRNA in spontaneously hypertensive rats

FEBS Letters

Anand-Srivastava, Madhu B.¹  Thibault, Christelle¹ 

[1] Department of Physiology, Faculty of Medicine, Université de Montréal, C.P. 6128, Succursale A, Montréal, Que., Canada

关键词: G-protein;    mRNA;    Heart;    Aorta;    Hypertension;    Gs;    stimulatory guanine nucleotide regulatory protein;    Giα-1;    inhibitory guanine nucleotide regulatory protein;    Giα-1;    Giα-2;    Giα-3;    isoforms of inhibitory guanine nucleotide regulatory protein encoded by these distinct genes;    WKY;    Wistar—Kyoto rats;    SHR;    spontaneously hypertensive rats;    mRNA;    messenger ribonucleic;    rRNA;    ribosomal ribonucleic acid;   

DOI  :  10.1016/0014-5793(92)81435-O

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have recently demonstrated that the decreased ability of hormones, forskolin and GTP to stimulate adenylate cyclase in heart and aorta from spontaneously hypertensive rats (SHR), as compared to their age-matched Wistar—Kyoto control rats (WKY), was associated with enhanced levels of Gi- and not with Gs-regulatory proteins. In the present studies we have investigated the expression of Gi-regulatory proteins at the mRNA level by Northern blotting. Total RNA of heart ventricle and aorta from WKY and SHR was probed with radiolabeled cDNA inserts encoding Giα-2 and Giα-3. The Giα-2 and Giα-3 probes detected a message of 2–3 and 3–5 kb, respectively, in both WKY and SHR, however, the message was significantly enhanced in SHR, as compared by WKY. On the other hand the cDNA probe encoding Gs_α detected a message of 1.8 kb in heart and aorta from both WKY and SHR, however, no difference in the levels of Gs_α mRNA was detected in SHR and WKY tissues. These results indicate that the mRNA levels of Giα-2 and Giα-3 and not of Gs are overexpressed in heart and aorta from SHR, which may be responsible for the increased levels of Gi as shown earlier by immunoblotting techniques. It may be suggested that the enhanced vascular tone and impaired cardiac contractility in hypertension may partly be the consequences of increased levels of Gi in heart and aorta.

【 授权许可】

Unknown