4.4 Article

Muscle- and fibre type-specific expression of glucose transporter 4, glycogen synthase and glycogen phosphorylase proteins in human skeletal muscle

Journal

PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY
Volume 447, Issue 4, Pages 452-456

Publisher

SPRINGER HEIDELBERG
DOI: 10.1007/s00424-003-1195-8

Keywords

single muscle fibres; glucose transporter 4; glycogen synthase; glycogen phosphorylase; myosin heavy chain isoforms

Categories

Ask authors/readers for more resources

The muscle- and fibre type-specific expression of skeletal muscle glucose transporter 4 (GLUT4), glycogen synthase (GS) and glycogen phosphorylase (GP) was investigated in six young male subjects. Single muscle fibres were dissected from vastus lateralis (VL), soleus (SO) and triceps brachii (TB) muscle biopsy samples. On the basis of myosin heavy chain (MHC) expression, fibres were pooled into three groups (MHC I, MHC IIA and MHC IIX) and the GLUT4, GS and GP content of 15-40 pooled fibres determined using SDS-PAGE and immunological detection. In VL, the GLUT4 content in the pooled muscle fibres expressing MHC I was similar to33% higher (P<0.05) than in fibres expressing MHC IIA or IIX. There was no difference in GLUT4 content between fibres expressing MHC IIA or IIX, nor were there any differences in GS and GP content between any of the fibre types. In SO, there was no difference in GLUT4, GS and GP between fibres expressing MHC I or IIA. No fibres expressing type IIX were detected. In TB, fibres expressing MHC IIA and IIX had significantly (P<0.05) more GP (66% and 55 % in MHC IIA and MHCIIX, respectively) than those expressing MHC I, whilst there was no difference in GP between MHC IIA and MHC IIX fibres. The GLUT4 and the GS content was similar in fibres expressing MHC I, IIA and IIX in the TB. Our data directly demonstrate that some proteins, like GLUT4 and GP, are expressed in a fibre type-specific manner in some, but not all, muscles, whilst other proteins, like GS, are not. In human skeletal muscle the GLUT4, GS and GP content thus seems to be related primarily to factors other than the fibre type as defined by the expression of contractile protein. These findings imply that it is not possible to generalize fibre type-dependent protein expression on the basis of biopsies from only one muscle.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.4
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available