TY - JOUR
T1 - Catecholamine response is attenuated during moderate-intensity exercise in response to the "lactate clamp"
AU - Fattor, Jill A.
AU - Miller, Benjamin F.
AU - Jacobs, Kevin A.
AU - Brooks, George A.
PY - 2005/1/1
Y1 - 2005/1/1
N2 - Catecholamine release is known to be regulated by feedforward and feedback mechanisms. Norepinephrine (NE) and epinephrine (Epi) concentrations rise in response to stresses, such as exercise, that challenge blood glucose homeostasis. The purpose of this study was to assess the hypothesis that the lactate anion is involved in feedback control of catecholamine concentration. Six healthy active men (26 ± 2 yr, 82 ± 2 kg, 50.7 ± 2.1 ml·kg-1·min-1) were studied on five occasions after an overnight fast. Plasma concentrations of NE and Epi were determined during 90 min of rest and 90 min of exercise at 55% of peak O 2 consumption (V̇O2 peak) two times with exogenous lactate infusion (lactate clamp, LC) and two times without LC (CON). The blood lactate profile (∼4 mM) of a preliminary trial at 65% V̇ O2 peak (65%) was matched during the subsequent LC trials. In resting men, plasma NE concentration was not different between trials, but during exercise all conditions were different with 65% > CON > LC (65%: 2,115 ± 166 pg/ml, CON: 1,573 ± 153 pg/ml, LC: 930 ± 174 pg/ml, P < 0.05). Plasma Epi concentrations at rest were different between conditions, with LC less than 65% and CON (65%: 68 ± 9 pg/ml, CON: 59 ± 7 pg/ml, LC: 38 ± 10 pg/ml, P < 0.05). During exercise, Epi concentration showed the same trend (65%: 262 ± 37 pg/ml, CON: 190 ± 34 pg/ml, LC: 113.2 ± 23 pg/ml, P < 0.05). In conclusion, lactate attenuates the catecholamine response during moderate-intensity exercise, likely by feedback inhibition.
AB - Catecholamine release is known to be regulated by feedforward and feedback mechanisms. Norepinephrine (NE) and epinephrine (Epi) concentrations rise in response to stresses, such as exercise, that challenge blood glucose homeostasis. The purpose of this study was to assess the hypothesis that the lactate anion is involved in feedback control of catecholamine concentration. Six healthy active men (26 ± 2 yr, 82 ± 2 kg, 50.7 ± 2.1 ml·kg-1·min-1) were studied on five occasions after an overnight fast. Plasma concentrations of NE and Epi were determined during 90 min of rest and 90 min of exercise at 55% of peak O 2 consumption (V̇O2 peak) two times with exogenous lactate infusion (lactate clamp, LC) and two times without LC (CON). The blood lactate profile (∼4 mM) of a preliminary trial at 65% V̇ O2 peak (65%) was matched during the subsequent LC trials. In resting men, plasma NE concentration was not different between trials, but during exercise all conditions were different with 65% > CON > LC (65%: 2,115 ± 166 pg/ml, CON: 1,573 ± 153 pg/ml, LC: 930 ± 174 pg/ml, P < 0.05). Plasma Epi concentrations at rest were different between conditions, with LC less than 65% and CON (65%: 68 ± 9 pg/ml, CON: 59 ± 7 pg/ml, LC: 38 ± 10 pg/ml, P < 0.05). During exercise, Epi concentration showed the same trend (65%: 262 ± 37 pg/ml, CON: 190 ± 34 pg/ml, LC: 113.2 ± 23 pg/ml, P < 0.05). In conclusion, lactate attenuates the catecholamine response during moderate-intensity exercise, likely by feedback inhibition.
KW - Epinephrine
KW - Exogenous lactate infusion
KW - Fuel sensing
KW - Norepinephrine
KW - Sympathetic response
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U2 - 10.1152/ajpendo.00117.2004
DO - 10.1152/ajpendo.00117.2004
M3 - Article
C2 - 15328074
AN - SCOPUS:11144275204
VL - 288
SP - E143-E147
JO - American Journal of Physiology - Cell Physiology
JF - American Journal of Physiology - Cell Physiology
SN - 0363-6143
IS - 1 51-1
ER -