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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Differential sympathetic vasomotor control by spinal AT(1) and V1 a receptors in the acute phase of hemorrhagic shock

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Milanez, Maycon I. O. [1] ; Martins, Gustavo R. [1] ; Nishi, Erika E. [1] ; Bergamaschi, Cassia T. [1] ; Campos, Ruy R. [1]
Total Authors: 5
[1] Univ Fed Sao Paulo, Cardiovasc Div, Dept Physiol, Escola Paulista Med, Rua Botucatu 862, Ground Floor, BR-04023060 Sao Paulo, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: European Journal of Pharmacology; v. 866, JAN 5 2020.
Web of Science Citations: 0

The role of the renin-angiotensin-aldosterone system and arginine vasopressin (AVP) as humoral components in maintaining blood pressure (BP) during hemorrhagic shock (HS) is well established. However, little is known about the role of angiotensin II (Ang II) and AVP in the control of preganglionic sympathetic neuron activity. We studied the effects evoked by spinal Ang II type I (AT(1)) and V1a receptors antagonism on cardiovascular and sympathetic responses during HS. A catheter (PE-10) was inserted into the subarachnoid space and advanced to the T10-11 vertebral level in urethane-anesthetized rats. The effects of HS on BP, heart rate (HR), and renal and splanchnic sympathetic nerve activity (rSNA and sSNA, respectively) were analyzed in the presence or absence (HS rats) of intrathecally injected losartan (HS-Los rats) or V1a antagonist (HS-V1a rats). The right femoral artery was catheterized for bleeding. Using a 5 ml syringe, hemorrhage was maintained continuously until a BP reduction of similar to 50 mmHg was achieved. We found that bleeding caused a reflex increase in HR, rSNA and sSNA in the HS rats. However, such responses were attenuated in the HS-Los rats. HS-V1a rats showed a reflex increase in HR, rSNA and sSNA in terms of frequency (spikes/s) but not in amplitude. Nevertheless, the BP recovery of the groups was similar. Our data showed that spinal AT(1) receptors are essential for sympathoexcitation during the acute phase of HS. Moreover, spinal AVP seems to be a neuromodulator that controls the recruitment of spinal sympathetic vasomotor neurons during the acute phase of HS. (AU)

FAPESP's process: 18/02671-3 - Functional and molecular actions of renal nerve in experimental chronic renal failure
Grantee:Cassia Marta de Toledo Bergamaschi
Support type: Regular Research Grants
FAPESP's process: 18/01898-4 - Evaluation of brain-spinal projections in the temporal establishment of renal sympathetic hyperactivation in Renovascular Hypertension
Grantee:Maycon Igor de Oliveira Milanez
Support type: Scholarships in Brazil - Doctorate