Platelet-derived growth factor stimulates glucose transport in skeletal muscles of transgenic mice specifically expressing platelet-derived growth factor receptor in the muscle, but it does not affect blood glucose levels.
Insulin stimulates the disposal of blood glucose into skeletal muscle and adipose tissues by the translocation of GLUT4 from intracellular pools to the plasma membrane, and consequently the concentration of blood glucose levels decreases rapidly in vivo. Phosphatidylinositol (PI) 3-kinase and Akt play a pivotal role in the stimulation of glucose transport by insulin, but detailed mechanisms are unknown. We and others reported that not only insulin but also platelet-derived growth factor (PDGF) and epidermal growth factor facilitate glucose uptake through GLUT4 translocation by activation of PI 3-kinase and Akt in cultured cells. However, opposite results were also reported. We generated transgenic mice that specifically express the PDGF receptor in skeletal muscle. In these mice, PDGF stimulated glucose transport into skeletal muscle in vitro and in vivo. Thus, PDGF apparently shares with insulin some of the signaling molecules needed for the stimulation of glucose transport. The degree of glucose uptake in vivo reached approximately 60% of that by insulin injection in skeletal muscle, but blood glucose levels were not decreased by PDGF in these mice. Therefore, PDGF-induced disposal of blood glucose into skeletal muscle is insufficient for rapid decrease of blood glucose levels.
Yuasa
Tomoyuki
T
Division of Molecular Genetics, Institute for Enzyme Research, the University of Tokushima, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan.
Kakuhata
Rei
R
Kishi
Kazuhiro
K
Obata
Toshiyuki
T
Shinohara
Yasuo
Y
Bando
Yoshimi
Y
Izumi
Keisuke
K
Kajiura
Fumiko
F
Matsumoto
Mitsuru
M
Ebina
Yousuke
Y
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D006321:Heart / Q000502:physiology; D007328:Insulin / Q000494:pharmacology; D051379:Mice; D008822:Mice, Transgenic; D018482:Muscle, Skeletal / Q000502:physiology; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D011994:Recombinant Proteins / Q000494:pharmacology; D015398:Signal Transduction
D001786:Blood Glucose; D007328:Insulin; D010982:Platelet-Derived Growth Factor; D011994:Recombinant Proteins; D020797:Receptor, Platelet-Derived Growth Factor beta; D005947:Glucose