Interaction between angiotensin II and GABA in the spinal cord regulates sympathetic vasomotor activity in Goldblatt hypertension

Autor(es)

Milanez, Maycon I. O. ^[1] ; Nishi, Erika E. ^[1] ; Rocha, Antonio A. ^[1] ; Bergamaschi, Cassia T. ^[1] ; Campos, Ruy R. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Escola Paulista Med, Dept Physiol, Cardiovasc Div, Rua Botucatu, 862, Ground Floor, Sao Paulo 04023060, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Neuroscience Letters; v. 728, MAY 29 2020.
• Citações Web of Science: 0

Resumo

Previous studies have been described changes in brain regions contributing to the sympathetic vasomotor overactivity in Goldblatt hypertension (2K1C). Furthermore, changes in the spinal cord are also involved in the cardiovascular and autonomic dysfunction in renovascular hypertension, as intrathecal (i.t) administration of Losartan (Los) causes a robust hypotensive/sympathoinhibitory response in 2K1C but not in control rats. The present study evaluated the role of spinal gamma-aminobutyric acid (GABA)-ergic inputs in the control of sympathetic vasomotor activity in the 2K1C rats. Hypertension was induced by clipping the renal artery. After six weeks, a catheter (PE-10) was inserted into the subarachnoid space and advanced to the T10-11 vertebral level in urethane-anaesthetized rats. The effects of i.t injection of bicuculline (Bic) on blood pressure (BP), renal and splanchnic sympathetic nerve activity (rSNA and sSNA, respectively) were evaluated over 40 consecutive minutes in the presence or absence of spinal AT1 antagonism. I.t. Bic triggered a more intense pressor and sympathoexcitatory response in 2K1C rats, however, these responses were attenuated by previous i.t. Los. No differences in the gene expression of GAD 65 and GABA-A receptors subunits in the spinal cord segments were found. Thus, the sympathoexcitation induced by spinal GABA-A blockade is dependent of local AT1 receptor in 2K1C but not in control rats. Excitatory angiotensinergic inputs to sympathetic preganglionic neurons are tonic controlled by spinal GABAergic actions in Goldblatt hypertension. (AU)

• Processo FAPESP: 18/02671-3 - Ações funcionais e moleculares do nervo renal na doença renal crônica experimental
• Beneficiário: Cassia Marta de Toledo Bergamaschi
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 18/01898-4 - Avaliação das projeções encéfalo-espinais no estabelecimento temporal da hiperativação simpática renal na Hipertensão Renovascular
• Beneficiário: Maycon Igor de Oliveira Milanez
• Modalidade de apoio: Bolsas no Brasil - Doutorado