دورية
Angiotensin II desensitization and Ca2+ and Na+ fluxes in vascular smooth muscle cells
العنوان: | Angiotensin II desensitization and Ca2+ and Na+ fluxes in vascular smooth muscle cells |
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المؤلفون: | Aboulafia, J., Oshiro, M. E. M., Feres, T., Shimuta, S. I., Paiva, A. C. M. |
المصدر: | Pflügers Archiv European Journal of Physiology; November 1989, Vol. 415 Issue: 2 p230-234, 5p |
مستخلص: | The role of ion fluxes in angiotensin II (AII) desensitization (tachyphylaxis) was investigated by studying Na+ and Ca2+ translocation in cultured vascular smooth muscle cells from the rat aorta. The effects of AII were compared to those of [1-sarcosine]-AII (Sar1-AII), an analogue which also induces tachyphylaxis, and [2-lysine]-AII (Lys2-AII), an analogue that does not show this property. Maximally effective concentrations of the three peptides induced a rapid and transient increase in 45Ca2+ efflux, a rapid and sustained decrease in total cell Ca2+ and an increased Na+ permeability. Repeated treatments, at short intervals, with either of the three peptides abolished the effect on Ca2+ efflux, and this desensitization was slowly reversible. A 30-min rest period was sufficient for full recovery of the response of cells that were desensitized by Lys2AII, whereas the recovery from AII or Sar1AII-desensitization was still not complete after 60 min. Our results suggest that the difference in the behaviour of the “tachyphylactic” AII and Sar1-AII and the “non-tachyphylactic” Lys2-AII lays not in the production of different signals upon binding to the receptor, but in a difference in the hormone-receptor interaction itself. |
قاعدة البيانات: | Supplemental Index |
تدمد: | 00316768 14322013 |
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DOI: | 10.1007/BF00370597 |