PMID- 23951278
OWN - NLM
STAT- MEDLINE
DCOM- 20140821
LR  - 20211021
IS  - 1932-6203 (Electronic)
IS  - 1932-6203 (Linking)
VI  - 8
IP  - 8
DP  - 2013
TI  - Physical exercise performance in temperate and warm environments is decreased by 
      an impaired arterial baroreflex.
PG  - e72005
LID - 10.1371/journal.pone.0072005 [doi]
LID - e72005
AB  - The present study aimed to investigate whether running performance in different 
      environments is dependent on intact arterial baroreceptor reflexes. We also 
      assessed the exercise-induced cardiovascular and thermoregulatory responses in 
      animals lacking arterial baroafferent signals. To accomplish these goals, male 
      Wistar rats were subjected to sinoaortic denervation (SAD) or sham surgery (SHAM) 
      and had a catheter implanted into the ascending aorta to record arterial pressure 
      and a telemetry sensor implanted in the abdominal cavity to record core 
      temperature. After recovering from these surgeries, the animals were subjected to 
      constant- or incremental-speed exercises performed until the voluntary 
      interruption of effort under temperate (25 degrees  C) and warm (35 degrees  C) conditions. 
      During the constant-speed exercises, the running time until the rats were 
      fatigued was shorter in SAD rats in both environments. Although the core 
      temperature was not significantly different between the groups, tail skin 
      temperature was higher in SAD rats under temperate conditions. The denervated 
      rats also displayed exaggerated increases in blood pressure and double product 
      compared with the SHAM rats; in particular, in the warm environment, these 
      exaggerated cardiovascular responses in the SAD rats persisted until they were 
      fatigued. These SAD-mediated changes occurred in parallel with increased 
      variability in the very low and low components of the systolic arterial pressure 
      power spectrum. The running performance was also affected by SAD during the 
      incremental-speed exercises, with the maximal speed attained being decreased by 
      approximately 20% in both environments. Furthermore, at the maximal power output 
      tolerated during the incremental exercises, the mean arterial pressure, heart 
      rate and double product were exaggerated in the SAD relative to SHAM rats. In 
      conclusion, the chronic absence of the arterial baroafferents accelerates 
      exercise fatigue in temperate and warm environments. Our findings also suggest 
      that an augmented cardiovascular strain accounted for the early interruption of 
      exercise in the SAD rats.
FAU - Pires, Washington
AU  - Pires W
AD  - Exercise Physiology Laboratory, Department of Physical Education, School of 
      Physical Education, Physiotherapy and Occupational Therapy, Universidade Federal 
      de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
FAU - Wanner, Samuel P
AU  - Wanner SP
FAU - Lima, Milene R M
AU  - Lima MR
FAU - Fonseca, Ivana A T
AU  - Fonseca IA
FAU - Fumega, Ubirajara
AU  - Fumega U
FAU - Haibara, Andrea S
AU  - Haibara AS
FAU - Coimbra, Candido C
AU  - Coimbra CC
FAU - Lima, Nilo R V
AU  - Lima NR
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20130807
PL  - United States
TA  - PLoS One
JT  - PloS one
JID - 101285081
SB  - IM
MH  - Analysis of Variance
MH  - Animals
MH  - Arteries/*physiopathology
MH  - Baroreflex/*physiology
MH  - Blood Pressure/physiology
MH  - Body Temperature Regulation/physiology
MH  - Denervation
MH  - Heart Rate/physiology
MH  - Male
MH  - Physical Conditioning, Animal/*physiology
MH  - Rats
MH  - Rats, Wistar
MH  - Running/*physiology
MH  - Sinoatrial Node/innervation/physiopathology
MH  - Temperature
PMC - PMC3737155
COIS- Competing Interests: The authors have declared that no competing interests exist.
EDAT- 2013/08/21 06:00
MHDA- 2014/08/22 06:00
PMCR- 2013/08/07
CRDT- 2013/08/17 06:00
PHST- 2013/04/16 00:00 [received]
PHST- 2013/07/10 00:00 [accepted]
PHST- 2013/08/17 06:00 [entrez]
PHST- 2013/08/21 06:00 [pubmed]
PHST- 2014/08/22 06:00 [medline]
PHST- 2013/08/07 00:00 [pmc-release]
AID - PONE-D-13-15667 [pii]
AID - 10.1371/journal.pone.0072005 [doi]
PST - epublish
SO  - PLoS One. 2013 Aug 7;8(8):e72005. doi: 10.1371/journal.pone.0072005. eCollection 
      2013.