Hypotensive effect induced by microinjection of Alamandine, a derivative of angiotensin-(1–7), into caudal ventrolateral medulla of 2K1C hypertensive rats.
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Date
2017
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Abstract
In the present study we evaluated the cardiovascular effects produced by microinjection of the new component
of the renin-angiotensin system, alamandine, into caudal ventrolateral medulla of urethane-anesthetized normotensive
and hypertensive 2K1C rats. The participation of different angiotensin receptors in the effects of
alamandine was also evaluated. Microinjection of angiotensin-(1–7) was used for comparison. The microinjection
of 4, 40 and 140 pmol of alamandine or angiotensin-(1–7) into caudal ventrolateral medulla induced similar
hypotensive effects in Sham-operated rats. However, contrasting with angiotensin-(1–7), in 2K1C rats the MAP
response to the highest dose of alamandine was similar to that observed with saline. The microinjection of A-
779, a selective Mas receptor antagonist, blunted the angiotensin-(1–7) effects but did not block the hypotensive
effect of alamandine in Sham or in 2K1C rats. However, microinjection of D-Pro7-angiotensin-(1–7), a Mas/MrgD
receptor antagonist, blocked the hypotensive effect induced by both peptides. Furthermore, microinjection of
PD123319, a putative AT2 receptor antagonist blocked the hypotensive effect of alamandine, but not of angiotensin-(
1–7), in Sham and 2K1C rats. Microinjection of the AT1 receptor antagonist, losartan, did not alter the
hypotensive effect of angiotensin-(1–7) or alamandine in both groups. These results provide new insights about
the differential mechanisms participating in the central cardiovascular effects of alamandine and angiotensin-
(1–7) in normotensive and 2K1C hypertensive rats.
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Keywords
Alamandine, Angiotensinergic antagonists, Caudal ventrolateral medulla, Ang-(1–7)
Citation
SOARES, E. R. et al. Hypotensive effect induced by microinjection of Alamandine, a derivative of angiotensin-(1–7), into caudal ventrolateral medulla of 2K1C hypertensive rats. Peptides, v. 96, p. 67-75, 2017. Disponível em: <https://www.sciencedirect.com/science/article/pii/S0196978117302772?via%3Dihub> Acesso em: 05 abr. 2018.