TY - JOUR
T1 - Reflex control of glucoregulatory exercise responses by group III and IV muscle afferents
AU - Vissing, J.
AU - Iwamoto, G. A.
AU - Fuchs, I. E.
AU - Galbo, H.
AU - Mitchell, J. H.
PY - 1994
Y1 - 1994
N2 - Group III and IV muscle afferents are active during exercise and relay information from mechano- and metaboreceptors in muscle. We hypothesized that these afferents participate in the regulation of endocrine and metabolic adjustments to exercise. Muscle branches of the femoral nerves were electrically stimulated in 10 anesthetized and paralyzed cats at 3, 20, and 140 times motor threshold, for 10 min at each intensity, recruiting group III afferents at 20 times motor threshold and group III and IV afferents at 140 times motor threshold. Six cats were not stimulated but were otherwise treated as stimulated cats. [3-3H]glucose was infused intravenously, and arterial blood was sampled for analysis of substrates and hormones. Three times motor threshold stimulation induced no changes in measured metabolic parameters. Twenty times motor threshold stimulation elicited increases (P < 0.05 vs. control) in glucose production (8.2 ± 1.8 μmol · min-1 · kg- 1) and plasma glucose (0.29 ± 0.07 mmol/l) and adrenocorticotropic hormone (ACTH; 35 ± 12 pg/ml). Stimulation at 140 times motor threshold elicited increases (P < 0.05 vs. control) in glucose production (10.2 ± 5.4 μmol · min-1 · kg-1), plasma glucose (0.53 ± 0.10 mmol/l), ACTH (94 ± 28 pg/ml), β-endorphin (17 ± 6 pg/ml), and Met-enkephalin (15 ± 2 pg/ml) and decreases (P < 0.05 vs. control) in insulin (0.65 ± 0.14 μU/ml). Glycerol and glucagon did not change with stimulations. The findings provide evidence for a reflex control from muscle of hormone secretion and mobilization of glucose during exercise.
AB - Group III and IV muscle afferents are active during exercise and relay information from mechano- and metaboreceptors in muscle. We hypothesized that these afferents participate in the regulation of endocrine and metabolic adjustments to exercise. Muscle branches of the femoral nerves were electrically stimulated in 10 anesthetized and paralyzed cats at 3, 20, and 140 times motor threshold, for 10 min at each intensity, recruiting group III afferents at 20 times motor threshold and group III and IV afferents at 140 times motor threshold. Six cats were not stimulated but were otherwise treated as stimulated cats. [3-3H]glucose was infused intravenously, and arterial blood was sampled for analysis of substrates and hormones. Three times motor threshold stimulation induced no changes in measured metabolic parameters. Twenty times motor threshold stimulation elicited increases (P < 0.05 vs. control) in glucose production (8.2 ± 1.8 μmol · min-1 · kg- 1) and plasma glucose (0.29 ± 0.07 mmol/l) and adrenocorticotropic hormone (ACTH; 35 ± 12 pg/ml). Stimulation at 140 times motor threshold elicited increases (P < 0.05 vs. control) in glucose production (10.2 ± 5.4 μmol · min-1 · kg-1), plasma glucose (0.53 ± 0.10 mmol/l), ACTH (94 ± 28 pg/ml), β-endorphin (17 ± 6 pg/ml), and Met-enkephalin (15 ± 2 pg/ml) and decreases (P < 0.05 vs. control) in insulin (0.65 ± 0.14 μU/ml). Glycerol and glucagon did not change with stimulations. The findings provide evidence for a reflex control from muscle of hormone secretion and mobilization of glucose during exercise.
KW - adrenocorticotropic hormone
KW - cat
KW - femoral nerve stimulation
KW - glucose homeostasis
KW - insulin
KW - methionine enkephalin
KW - β-endorphin
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U2 - 10.1152/ajpregu.1994.266.3.r824
DO - 10.1152/ajpregu.1994.266.3.r824
M3 - Article
C2 - 8160877
AN - SCOPUS:0027951101
SN - 0002-9513
VL - 266
SP - R824-R830
JO - American Journal of Physiology - Regulatory Integrative and Comparative Physiology
JF - American Journal of Physiology - Regulatory Integrative and Comparative Physiology
IS - 3 35-3
ER -