Angiotensin-(1-7) in the Rostral Ventrolateral Medulla Modulates Enhanced CardiacSympathetic Afferent Reflex and Sympathetic Activation in Renovascular Hypertensive Rats

Peng Li, Hai-Jian Sun, Bai-Ping Cui, Ye-Bo Zhou and Ying Han
Hypertension. 2013;61:820-827; originally published online February 19, 2013;
doi: 10.1161/HYPERTENSIONAHA.111.00191 The purpose of this was to determine whether ang 1-7 in the RVLM is involved in the enhanced CSAR in renovascular hypertension.  Secondly to determine whether cAMP – PKA pathway is playing a role in mediating the ang1-7 effects on the CSAR in the RVLM of renovascular hypertensive rats.   What they determined from the study is that in the renovascular hypertensive model not only demonstrate enhanced RSNA and map responses; they also found enhanced mas receptor expression and also that by blocking Ang 1-7 with the antagonist A-779 that the CSAR is blocked. Finally to determine if CAMP-PKA pathway is involved they gave inhibitors to PKA and showed that greater responses in RSNA and MAP were greater in the hypertensive model. The same result was demonstrated with the cAMP antagonist except that with pretreatment of cAMP the CSAR response was not abolished however it was with the PKA antagonists.  cAMP levels were also enhanced in response to activation of the CSAR.   They basically showed that Ang 1-7 in the RVLM enhances the CSR along with RSNA and MAP. This is done by acting on MAS receptors which ultimately lead to activation of the cAMP-PKA pathway.