[7-D-ALA]-angiotensin-(1-7): selective antagonism of angiotensin-(1-7) in the rat paraventricular nucleus.
Microiontophoretic application of both, the octapeptide angiotensin II (Ang II) and its N-terminal heptapeptide angiotensin-(1-7), [Ang-(1-7)], has been shown to increase the firing rate of rat hypothalamic paraventricular neurones. In the present microiontophoretic study, the effect of the angiotensin analogue [7-D-Ala]-Ang-(1-7) on Ang II- and Ang-(1-7)-induced firing rate increase of paraventricular neurones has been tested. While the response to Ang II was unchanged, the response to Ang-(1-7) was effectively blocked by [7-D-Ala]-Ang-(1-7). The results indicate that the Ang-(1-7)-induced excitation of paraventricular neurones may be mediated by a distinct Ang-(1-7)-receptor and that [7-D-Ala]-Ang-(1-7) is a selective antagonist of this receptor.
Division of Neurobiology, University of Berne, Switzerland.
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Ambühl
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Felix
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Khosla
D000200:Action Potentials / Q000187:drug effects; D000803:Angiotensin I; D000804:Angiotensin II / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors* / Q000378:metabolism / Q000494:pharmacology; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D010446:Peptide Fragments / Q000037:antagonists & inhibitors* / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011945:Receptors, Angiotensin / Q000378:metabolism
C092006:7-Ala-angiotensin (1-7); D057911:Angiotensin Receptor Antagonists; D010446:Peptide Fragments; D011945:Receptors, Angiotensin; D000804:Angiotensin II; D000803:Angiotensin I; C118790:angiotensin I (1-7)