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Santiago HP, Leite LHR, Lima PMA, Fóscolo DRC, Natali AJ, Prímola-Gomes TN, Szawka RE, Coimbra CC. Effects of physical training on hypothalamic neuronal activation and expressions of vasopressin and oxytocin in SHR after running until fatigue. Pflugers Arch 2024; 476:365-377. [PMID: 38308122 DOI: 10.1007/s00424-024-02916-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 01/24/2024] [Accepted: 01/25/2024] [Indexed: 02/04/2024]
Abstract
To assess the influence of physical training on neuronal activation and hypothalamic expression of vasopressin and oxytocin in spontaneously hypertensive rats (SHR), untrained and trained normotensive rats and SHR were submitted to running until fatigue while internal body and tail temperatures were recorded. Hypothalamic c-Fos expression was evaluated in thermoregulatory centers such as the median preoptic nucleus (MnPO), medial preoptic nucleus (mPOA), paraventricular nucleus of the hypothalamus (PVN), and supraoptic nucleus (SON). The PVN and the SON were also investigated for vasopressin and oxytocin expressions. Although exercise training improved the workload performed by the animals, it was reduced in SHR and followed by increased internal body temperature due to tail vasodilation deficit. Physical training enhanced c-Fos expression in the MnPO, mPOA, and PVN of both strains, and these responses were attenuated in SHR. Vasopressin immunoreactivity in the PVN was also increased by physical training to a lesser extent in SHR. The already-reduced oxytocin expression in the PVN of SHR was increased in response to physical training. Within the SON, neuronal activation and the expressions of vasopressin and oxytocin were reduced by hypertension and unaffected by physical training. The data indicate that physical training counterbalances in part the negative effect of hypertension on hypothalamic neuronal activation elicited by exercise, as well as on the expression of vasopressin and oxytocin. These hypertension features seem to negatively influence the workload performed by SHR due to the hyperthermia derived from the inability of physical training to improve heat dissipation through skin vasodilation.
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Affiliation(s)
- Henrique P Santiago
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Laura H R Leite
- Departamento de Biofísica e Fisiologia, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil
| | - Paulo M A Lima
- Núcleo de Pesquisa da Faculdade de Medicina da Universidade de Rio Verde, Universidade de Rio Verde, Campus Goiânia, Goiânia, Brazil
| | - Daniela R C Fóscolo
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Antônio José Natali
- Departamento de Educação Física, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | | | - Raphael E Szawka
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Cândido C Coimbra
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Belo Horizonte, MG, 31270-901, Brazil.
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Inhibition of nNOS in the paraventricular nucleus of hypothalamus decreases exercise-induced hyperthermia. Brain Res Bull 2021; 177:64-72. [PMID: 34536522 DOI: 10.1016/j.brainresbull.2021.09.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/21/2021] [Accepted: 09/10/2021] [Indexed: 11/23/2022]
Abstract
The paraventricular nucleus of the hypothalamus (PVN) is an important site for autonomic control, which integrates thermoregulation centers and sympathetic outflow to thermoeffector organs. PVN neurons express the neuronal isoform of nitric oxide synthase (nNOS) whose expression is locally upregulated by physical exercise. Thus, the aim of the present study was to evaluate the role of nNOS in the PVN in the exercise-induced hyperthermia. Seven days after surgery, male Wistar rats received bilateral intra-PVN microinjections of the selective nNOS inhibitor Nw-Propyl-L-Arginine (NPLA) or vehicle (saline) and were submitted to an acute progressive exercise session on a treadmill until fatigue. Abdominal and tail skin temperature (Tabd and Ttail, respectively) were measured, and the threshold (Hthr; °C) and sensitivity (Hsen) for heat dissipation calculated. Performance variables were also collected. During the progressive exercise protocol, all animals displayed an increase in the Tabd. However, compared to vehicle group, the microinjection of NPLA in the PVN attenuated the exercise-induced hyperthermia. There was no difference in Ttail or Hthr between NPLA and control rats. In contrast, Hsen was increased in the NPLA group compared to vehicle. In addition, heat storage was lower in NPLA-treated animals. Despite the temperature differences, inhibition of nNOS in the PVN did not affect running performance on the treadmill. These results suggest that nitrergic signaling within the PVN, under nNOS activation, drives the increase of body temperature, being necessary for the proper thermal regulatory mechanisms during progressive exercise-induced hyperthermia.
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de Souza JA, Becker LK, Batista MAC, de Assis Braga DC, Gomes PM, Alzamora AC, Vieira MAR, de Lima WG, Andrade MGC, de Lima Sanches B, Totou NL, de Assis Dias Martins Júnior F, de Oliveira LB, Antunes VR, Cardoso LM. Swimming training improves cardiovascular autonomic dysfunctions and prevents renal damage in rats fed a high-sodium diet from weaning. Exp Physiol 2020; 106:412-426. [PMID: 33347659 DOI: 10.1113/ep088892] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 12/03/2020] [Indexed: 01/03/2023]
Abstract
NEW FINDINGS What is the central question of this study? How does swimming exercise training impact hydro-electrolytic balance, renal function, sympathetic contribution to resting blood pressure and cerebrospinal fluid (CSF) [Na+ ] in rats fed a high-sodium diet from weaning? What is the main finding and its importance? An exercise-dependent reduction in blood pressure was associated with decreased CSF [Na+ ], sympathetically driven vasomotor tonus and renal fibrosis indicating that the anti-hypertensive effects of swimming training in rats fed a high-sodium diet might involve neurogenic mechanisms regulated by sodium levels in the CSF rather than changes in blood volume. ABSTRACT High sodium intake is an important factor associated with hypertension. High-sodium intake with exercise training can modify homeostatic hydro-electrolytic balance, but the effects of this association are mostly unknown. In this study, we sought to investigate the effects of swimming training (ST) on cerebrospinal fluid (CSF) Na+ concentration, sympathetic drive, blood pressure (BP) and renal function of rats fed a 0.9% Na+ (equivalent to 2% NaCl) diet with free access to water for 22 weeks after weaning. Male Wistar rats were assigned to two cohorts: (1) fed standard diet (SD) and (2) fed high-sodium (HS) diet. Each cohort was further divided into trained and sedentary groups. ST normalised BP levels of HS rats as well as the higher sympathetically related pressor activity assessed by pharmacological blockade of ganglionic transmission (hexamethonium). ST preserved the renal function and attenuated the glomerular shrinkage elicited by HS. No change in blood volume was found among the groups. CSF [Na+ ] levels were higher in sedentary HS rats but were reduced by ST. Our findings showed that ST effectively normalised BP of HS rats, independent of its effects on hydro-electrolytic balance, which might involve neurogenic mechanisms regulated by Na+ levels in the CSF as well as renal protection.
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Affiliation(s)
| | - Lenice Kappes Becker
- Physical Education School at the Federal University of Ouro Preto, Ouro Preto, MG, Brazil
| | | | | | - Paula Magalhães Gomes
- Deptartment of Physiology and Biophysics, ICB; University of São Paulo, São Paulo, SP, Brazil
| | - Andréia Carvalho Alzamora
- Department of Biological Sciences, ICEB at the Federal University of Ouro Preto, Ouro Preto, MG, Brazil
| | | | - Wanderson Geraldo de Lima
- Department of Biological Sciences, ICEB at the Federal University of Ouro Preto, Ouro Preto, MG, Brazil
| | | | - Bruno de Lima Sanches
- Department of Physiology and Biophysics, ICB; Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Nádia Lúcia Totou
- Department of Biological Sciences, ICEB at the Federal University of Ouro Preto, Ouro Preto, MG, Brazil
| | | | | | - Vagner Roberto Antunes
- Deptartment of Physiology and Biophysics, ICB; University of São Paulo, São Paulo, SP, Brazil
| | - Leonardo Máximo Cardoso
- Department of Biological Sciences, ICEB at the Federal University of Ouro Preto, Ouro Preto, MG, Brazil
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Lima PMA, Campos HO, Fóscolo DRC, Szawka RE, Wanner SP, Coimbra CC. The time-course of thermoregulatory responses during treadmill running is associated with running duration-dependent hypothalamic neuronal activation in rats. Brain Struct Funct 2019; 224:2775-2786. [DOI: 10.1007/s00429-019-01933-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 07/31/2019] [Indexed: 12/29/2022]
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Nuñez P, Diaz I, Perillan C, Arguelles J, Diaz E. Circadian urinary citrate excretion in a rat model of exercise. Life Sci 2017; 169:65-68. [DOI: 10.1016/j.lfs.2016.11.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 11/05/2016] [Accepted: 11/21/2016] [Indexed: 11/17/2022]
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Lima PM, Santiago HP, Szawka RE, Coimbra CC. Central blockade of nitric oxide transmission impairs exercise-induced neuronal activation in the PVN and reduces physical performance. Brain Res Bull 2014; 108:80-7. [DOI: 10.1016/j.brainresbull.2014.09.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 09/03/2014] [Accepted: 09/04/2014] [Indexed: 11/17/2022]
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