Exercise-induced neuroplasticity in autonomic nuclei restores the cardiac vagal tone and baroreflex dysfunction in aged hypertensive rats

Autor(es)

Dellacqua, Lais Oliveira ; Gomes, Paula Magalhaes ; Batista, Julia Santos ; Michelini, Lisete Compagno ; Antunes, Vagner Roberto

• Tipo de documento: Artigo Científico
• Fonte: Journal of Applied Physiology; v. 136, n. 1, p. 10-pg., 2024-01-07.

Resumo

Aging is accompanied by considerable deterioration of homeostatic systems, such as autonomic imbalance characterized by heightened sympathetic activity, lower parasympathetic tone, and depressed heart rate (HR) variability, which are aggravated by hypertension. Here, we hypothesized that these age-related deficits in aged hypertensive rats can be ameliorated by exercise training, with benefits to the cardiovascular system. Therefore, male 22-mo-old spontaneously hypertensive rats (SHRs) and age-matched Wistar Kyoto (WKY) submitted to moderate-intensity exercise training (T) or kept sedentary (S) for 8 wk were evaluated for hemodynamic/autonomic parameters, baroreflex sensitivity, cardiac sympathetic/parasympathetic tone and analysis of dopamine beta-hydroxylase (DBH+) and oxytocin (OT+) pathways of autonomic brain nuclei. Aged SHR-S versus WKY-S exhibited elevated mean arterial pressure (MAP: +51%) and HR (+20%), augmented pressure/HR variability, no cardiac vagal tone, and depressed reflex control of the heart (HR range, -28%; gain, -49%). SHR-T exhibited a lower resting HR, a partial reduction in the MAP (-14%), in the pressure/HR variabilities, and restored parasympathetic modulation, with improvement of baroreceptor reflex control when compared with SHR-S. Exercise training increased the ascending DBH+ projections conveying peripheral information to the paraventricular nucleus of hypothalamus (PVN), augmented the expression of OT+ neurons, and reduced the density of DBH+ neurons in the rostral ventrolateral medulla (RVLM) of SHR-T. Data indicate that exercise training induces beneficial neuroplasticity in brain autonomic circuitry, and it is highly effective to restore the parasympathetic tone, and attenuation of age-related autonomic imbalance and baroreflex dysfunction, thus conferring long-term benefits for cardiovascular control in aged hypertensive individuals. (AU)

• Processo FAPESP: 12/22368-7 - Estudo de alterações na expressão gênica de núcleos hipotalâmicos e bulbares de SHR em envelhecimento submetidos a treinamento aeróbio e sua correlação com o controle neural da circulação
• Beneficiário: Laís Oliveira Dellacqua
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 22/07465-8 - Micróglia na modulação dos efeitos deletérios da hipertensão sobre a permeabilidade da barreira hematoencefálica (BHE): efeitos do treinamento aeróbio
• Beneficiário: Paula Magalhães Gomes
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/06206-0 - Estudo da expressão gênica de neuropeptídeos e mediadores inflamatórios em núcleos do eixo hipotálamo-tronco cerebral envolvidos no controle neural da pressão arterial de animais submetidos a dieta obesogênica
• Beneficiário: Vagner Roberto Antunes
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 18/14544-6 - Barreira hematoencefálica: um novo paradigma no tratamento da hipertensão
• Beneficiário: Lisete Compagno Michelini
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 11/51410-9 - Amelioration of the autonomic imbalances of old age with exercise: exploring the molecular and physiological mechanisms
• Beneficiário: Lisete Compagno Michelini
• Modalidade de apoio: Auxílio à Pesquisa - Temático