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Sinoaortic denervation prevents enhanced heat loss induced by central cholinergic stimulation during physical exercise

Pires, Washington; Wanner, Samuel P; Lima, Milene R M; Moreira Soares Oliveira, Bernardo LU ; Guimarães, Juliana B; de Lima, Daniel C; Haibara, Andréa S; Rodrigues, Luiz O C; Coimbra, Cândido C and Lima, Nilo R V (2010) In Brain Research1966-01-01+01:00 1366. p.8-120
Abstract

The present study investigated whether the effects of central cholinergic stimulation on thermoregulation during exercise are modulated by arterial baroreceptors. Wistar rats were submitted to sinoaortic denervation (SAD) or sham denervation (SHAM) and then fitted with a chronic guide cannula into the lateral cerebral ventricle. After 2 weeks, a catheter was implanted into the ascending aorta, and a temperature sensor was implanted into the peritoneal cavity. Two days later, the rats were submitted to exercise on a treadmill at 18 m/min until fatigued. Thermoregulatory and cardiovascular responses were measured after injection of 2 μL of 10mM physostigmine (Phy) or 0.15M NaCl solution (Sal) into the cerebral ventricle. In SHAM rats, Phy... (More)

The present study investigated whether the effects of central cholinergic stimulation on thermoregulation during exercise are modulated by arterial baroreceptors. Wistar rats were submitted to sinoaortic denervation (SAD) or sham denervation (SHAM) and then fitted with a chronic guide cannula into the lateral cerebral ventricle. After 2 weeks, a catheter was implanted into the ascending aorta, and a temperature sensor was implanted into the peritoneal cavity. Two days later, the rats were submitted to exercise on a treadmill at 18 m/min until fatigued. Thermoregulatory and cardiovascular responses were measured after injection of 2 μL of 10mM physostigmine (Phy) or 0.15M NaCl solution (Sal) into the cerebral ventricle. In SHAM rats, Phy injection induced a greater exercise-induced increase in blood pressure and lower increase in heart rate than Sal treatment. In the SAD group, the attenuation of heart rate in response to Phy was blocked despite an exaggerated increase in blood pressure. SHAM rats treated with Phy had a higher increase in tail skin temperature compared to Sal injection (31.9 ± 0.4 °C Phy-SHAM vs. 30.1 ± 0.6 °C Sal-SHAM, 5 min after injection; p<0.05), resulting in a lower exercise-induced increase in core temperature. In contrast, SAD blocked the Phy injection effects in thermoregulatory responses during exercise (tail temperature: 30.1 ± 1.2 °C Phy-SAD vs. 29.5 ± 1.2 °C Sal-SAD, 5 min, p = 0.65). Therefore, we conclude that the enhancement of cutaneous heat loss induced by central cholinergic stimulation during exercise is mediated primarily by arterial baroreceptors.

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published
keywords
Acetylcholine, Analysis of Variance, Animals, Autonomic Nervous System, Blood Pressure, Body Temperature, Body Temperature Regulation, Cholinesterase Inhibitors, Denervation, Dose-Response Relationship, Drug, Exercise Test, Heart Rate, Injections, Intraventricular, Male, Physical Conditioning, Animal, Physostigmine, Rats, Rats, Wistar, Sinoatrial Node, Statistics as Topic, Journal Article, Research Support, Non-U.S. Gov't
in
Brain Research1966-01-01+01:00
volume
1366
pages
9 pages
publisher
Elsevier
external identifiers
  • scopus:79251615001
ISSN
1872-6240
DOI
10.1016/j.brainres.2010.09.110
language
English
LU publication?
no
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cf393279-7bd4-4705-85fc-bf931233bc8f
date added to LUP
2017-03-08 14:46:52
date last changed
2018-05-29 12:05:08
@article{cf393279-7bd4-4705-85fc-bf931233bc8f,
  abstract     = {<p>The present study investigated whether the effects of central cholinergic stimulation on thermoregulation during exercise are modulated by arterial baroreceptors. Wistar rats were submitted to sinoaortic denervation (SAD) or sham denervation (SHAM) and then fitted with a chronic guide cannula into the lateral cerebral ventricle. After 2 weeks, a catheter was implanted into the ascending aorta, and a temperature sensor was implanted into the peritoneal cavity. Two days later, the rats were submitted to exercise on a treadmill at 18 m/min until fatigued. Thermoregulatory and cardiovascular responses were measured after injection of 2 μL of 10mM physostigmine (Phy) or 0.15M NaCl solution (Sal) into the cerebral ventricle. In SHAM rats, Phy injection induced a greater exercise-induced increase in blood pressure and lower increase in heart rate than Sal treatment. In the SAD group, the attenuation of heart rate in response to Phy was blocked despite an exaggerated increase in blood pressure. SHAM rats treated with Phy had a higher increase in tail skin temperature compared to Sal injection (31.9 ± 0.4 °C Phy-SHAM vs. 30.1 ± 0.6 °C Sal-SHAM, 5 min after injection; p&lt;0.05), resulting in a lower exercise-induced increase in core temperature. In contrast, SAD blocked the Phy injection effects in thermoregulatory responses during exercise (tail temperature: 30.1 ± 1.2 °C Phy-SAD vs. 29.5 ± 1.2 °C Sal-SAD, 5 min, p = 0.65). Therefore, we conclude that the enhancement of cutaneous heat loss induced by central cholinergic stimulation during exercise is mediated primarily by arterial baroreceptors.</p>},
  author       = {Pires, Washington and Wanner, Samuel P and Lima, Milene R M and Moreira Soares Oliveira, Bernardo and Guimarães, Juliana B and de Lima, Daniel C and Haibara, Andréa S and Rodrigues, Luiz O C and Coimbra, Cândido C and Lima, Nilo R V},
  issn         = {1872-6240},
  keyword      = {Acetylcholine,Analysis of Variance,Animals,Autonomic Nervous System,Blood Pressure,Body Temperature,Body Temperature Regulation,Cholinesterase Inhibitors,Denervation,Dose-Response Relationship, Drug,Exercise Test,Heart Rate,Injections, Intraventricular,Male,Physical Conditioning, Animal,Physostigmine,Rats,Rats, Wistar,Sinoatrial Node,Statistics as Topic,Journal Article,Research Support, Non-U.S. Gov't},
  language     = {eng},
  month        = {12},
  pages        = {8--120},
  publisher    = {Elsevier},
  series       = {Brain Research1966-01-01+01:00},
  title        = {Sinoaortic denervation prevents enhanced heat loss induced by central cholinergic stimulation during physical exercise},
  url          = {http://dx.doi.org/10.1016/j.brainres.2010.09.110},
  volume       = {1366},
  year         = {2010},
}