Differences in autonomic innervation to the vertebrobasilar arteries in spontaneously hypertensive and Wistar rats

Autor(es)

Roloff, Eva V. L. ^[1] ; Walas, Dawid ^[1] ; Moraes, Davi J. A. ^[2] ; Kasparov, Sergey ^[1] ; Paton, Julian F. R. ^{[1, 3]}

Afiliação do(s) autor(es)

^[1] Univ Bristol, Biomed Sci, Sch Physiol Pharmacol & Neurosci, Bristol BS8 1TD, Avon - England

^[2] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Physiol, BR-14049900 Ribeirao Preto, SP - Brazil

^[3] Univ Auckland, Fac Med & Hlth Sci, Dept Physiol, 85 Pk Rd, Auckland 1142 - New Zealand

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF PHYSIOLOGY-LONDON; v. 596, n. 16, p. 3505-3529, AUG 15 2018.
• Citações Web of Science: 2

Resumo

Neurogenic hypertension may result from brainstem hypoperfusion. We previously found remodelling (decreased lumen, increased wall thickness) in vertebrobasilar arteries of juvenile, pre-hypertensive spontaneously hypertensive (PHSH) and adult spontaneously hypertensive (SH) rats compared to age-matched normotensive rats. We tested the hypothesis that there would be a greater density of sympathetic to parasympathetic innervation of vertebrobasilar arteries in SH versus Wistar rats irrespective of the stage of development and that sympathetic denervation (ablation of the superior cervical ganglia bilaterally) would reverse the remodelling and lower blood pressure. Contrary to our hypothesis, immunohistochemistry revealed a decrease in the innervation density of noradrenergic sympathetic fibres in adult SH rats (P < 0.01) compared to Wistar rats. Unexpectedly, there was a 65% deficit in parasympathetic fibres, as assessed by both vesicular acetylcholine transporter (alpha-VAChT) and vasoactive intestinal peptide (alpha-VIP) immunofluorescence (P < 0.002) in PHSH rats compared to age-matched Wistar rats. Although the neural activity of the internal cervical sympathetic branch, which innervates the vertebrobasilar arteries, was higher in PHSH relative toWistar rats, its denervation had no effect on the vertebrobasilar artery morphology or persistent effect on arterial pressure in SH rats. Our neuroanatomic and functional data do not support a role for sympathetic nerves in remodelling of the vertebrobasilar artery wall in PHSH or SH rats. The remodelling of vertebrobasilar arteries and the elevated activity in the internal cervical sympathetic nerve coupled with their reduced parasympathetic innervation suggests a compromised vasodilatory capacity in PHSH and SH rats that could explain their brainstem hypoperfusion. (AU)

• Processo FAPESP: 13/10484-5 - Caracterização eletrofisiológica e molecular dos neurônios envolvidos na geração do ritmo e do padrão respiratório de ratos durante o desenvolvimento pós-natal
• Beneficiário: Davi José de Almeida Moraes
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores