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Nitric oxide is required for the insulin sensitizing effects of contraction in mouse skeletal muscle
Author(s) -
Zhang Xinmei,
Hiam Danielle,
Hong YetHoi,
Zulli Anthony,
Hayes Alan,
Rattigan Stephen,
McConell Glenn K.
Publication year - 2017
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jp275133
Subject(s) - medicine , skeletal muscle , endocrinology , insulin , contraction (grammar) , insulin resistance , nitric oxide , glucose uptake , basal (medicine) , muscle contraction , nitric oxide synthase , ex vivo , chemistry , biology , in vitro , biochemistry
Key points People with insulin resistance or type 2 diabetes can substantially increase their skeletal muscle glucose uptake during exercise and insulin sensitivity after exercise. Skeletal muscle nitric oxide (NO) is important for glucose uptake during exercise, although how prior exercise increases insulin sensitivity is unclear. In the present study, we examined whether NO is necessary for normal increases in skeletal muscle insulin sensitivity after contraction ex vivo in mouse muscle. The present study uncovers, for the first time, a novel role for NO in the insulin sensitizing effects of ex vivo contraction, which is independent of blood flow.Abstract The factors regulating the increase in skeletal muscle insulin sensitivity after exercise are unclear. We examined whether nitric oxide (NO) is required for the increase in insulin sensitivity after ex vivo contractions. Isolated C57BL/6J mouse EDL muscles were contracted for 10 min or remained at rest (basal) with or without the NO synthase (NOS) inhibition ( N G ‐monomethyl‐ l ‐arginine; l ‐NMMA; 100 μ m ). Then, 3.5 h post contraction/basal, muscles were exposed to saline or insulin (120 μU ml −1 ) with or without l ‐NMMA during the last 30 min. l ‐NMMA had no effect on basal skeletal muscle glucose uptake. The increase in muscle glucose uptake with insulin (57%) was significantly ( P < 0.05) greater after prior contraction (140% increase). NOS inhibition during the contractions had no effect on this insulin‐sensitizing effect of contraction, whereas NOS inhibition during insulin prevented the increase in skeletal muscle insulin sensitivity post‐contraction. Soluble guanylate cyclase inhibition, protein kinase G (PKG) inhibition or cyclic nucleotide phosphodiesterase inhibition each had no effect on the insulin‐sensitizing effect of prior contraction. In conclusion, NO is required for increases in insulin sensitivity several hours after contraction of mouse skeletal muscle via a cGMP/PKG independent pathway.