A Decrease in the Amount and Function of Inhibitory GTP-Binding Protein in the Resistance Small Artery From Spontaneously Hypertensive Rats

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Author(s)

Abstract

The inhibitory GTP-binding protein (Gi protein) plays an important role in regulation of vascular tone. Many studies have implicated the role of Gi protein in conduit vessels. However, the physiological role of Gi protein in the control of peripheral microvascular tone in hypertension has not been established yet. Therefore, we investigated the concentration of Gi protein in the peripheral resistance arteries and aorta in the spontaneously hypertensive rats (SHR), normotensive Wistar-Kyoto rats (WKY) and renovascular hypertensive rats (RHR), using immunohistochemical methods semiquantitatively. Changes in the function of Gi protein in relation to α<SUB>2</SUB>-adrenoceptor were also investigated by microcannulation techniques. We have shown that the amount of α<SUB>2</SUB> subunits of Gi protein in the cremaster small artery was significantly lower in SHR aged 4 weeks and older than in age-matched WKY and that there were no significant differences between RHR and WKY. We also demonstrated that the function of Gi protein in relation to α<SUB>2</SUB>-adrenoceptor was already lower in SHR before the onset of hypertension. The quantitative and functional decline in Gi protein in the smooth muscle cells of peripheral small arteries were observed in SHR even before the onset of hypertension, whereas rats with secondary hypertension did not exhibit this finding.

Journal

  • The Japanese Journal of Pharmacology

    The Japanese Journal of Pharmacology 79(2), 185-193, 1999-02-01

    The Japanese Pharmacological Society

References:  24

Cited by:  1

Codes

  • NII Article ID (NAID)
    10008682294
  • NII NACSIS-CAT ID (NCID)
    AA00691188
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    00215198
  • NDL Article ID
    4663481
  • NDL Source Classification
    ZS51(科学技術--薬学)
  • NDL Call No.
    Z53-D199
  • Data Source
    CJP  CJPref  NDL  J-STAGE 
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