TY - JOUR

T1 - Effect of in vivo injection of cholera and pertussis toxin on glucose transport in rat skeletal muscle

AU - Ploug, Thorkil

AU - Han, X

AU - Petersen, L N

AU - Galbo, H

PY - 1997/1

Y1 - 1997/1

N2 - Cholera toxin (CTX) and pertussis toxin (PTX) were examined for their ability to inhibit glucose transport in perfused skeletal muscle. Twenty-five hours after an intravenous injection of CTX, basal transport was decreased approximately 30%, and insulin- and contraction-stimulated transport was reduced at least 86 and 49%, respectively, in both the soleus and red and white gastrocnemius muscles. In contrast, PTX treatment was much less efficient. Impairment of glucose transport appeared to develop 10-15 h after CTX administration, which coincided with development of hyperglycemia despite hyperinsulinimia, increased plasma free fatty acid levels, increased adenosine 3',5'-cyclic monophosphate (cAMP) concentrations in muscle, but no difference in plasma catecholamines. Twenty-five hours after CTX treatment, GLUT-4 protein in both soleus and red gastrocnemius muscles was decreased, whereas no change in GLUT-1 protein content was found. In contrast, GLUT-4 mRNA was unchanged, but transcripts for GLUT-1 were increased > or = 150% in all three muscles from CTX-treated rats. The findings suggest that CTX via increased cAMP impairs basal as well as insulin- and contraction-stimulated muscle glucose transport, at least in part from a decrease in intramuscular GLUT-4 protein.

AB - Cholera toxin (CTX) and pertussis toxin (PTX) were examined for their ability to inhibit glucose transport in perfused skeletal muscle. Twenty-five hours after an intravenous injection of CTX, basal transport was decreased approximately 30%, and insulin- and contraction-stimulated transport was reduced at least 86 and 49%, respectively, in both the soleus and red and white gastrocnemius muscles. In contrast, PTX treatment was much less efficient. Impairment of glucose transport appeared to develop 10-15 h after CTX administration, which coincided with development of hyperglycemia despite hyperinsulinimia, increased plasma free fatty acid levels, increased adenosine 3',5'-cyclic monophosphate (cAMP) concentrations in muscle, but no difference in plasma catecholamines. Twenty-five hours after CTX treatment, GLUT-4 protein in both soleus and red gastrocnemius muscles was decreased, whereas no change in GLUT-1 protein content was found. In contrast, GLUT-4 mRNA was unchanged, but transcripts for GLUT-1 were increased > or = 150% in all three muscles from CTX-treated rats. The findings suggest that CTX via increased cAMP impairs basal as well as insulin- and contraction-stimulated muscle glucose transport, at least in part from a decrease in intramuscular GLUT-4 protein.

KW - Animals

KW - Biological Transport

KW - Catecholamines

KW - Cholera Toxin

KW - Cyclic AMP

KW - Glucose

KW - Glucose Transporter Type 1

KW - Glucose Transporter Type 4

KW - Injections, Intravenous

KW - Insulin

KW - Male

KW - Monosaccharide Transport Proteins

KW - Muscle Contraction

KW - Muscle Proteins

KW - Muscle, Skeletal

KW - Pertussis Toxin

KW - RNA, Messenger

KW - Rats

KW - Rats, Wistar

KW - Virulence Factors, Bordetella

M3 - Journal article

C2 - 9038845

VL - 272

SP - E7-17

JO - American Journal of Physiology - Cell Physiology

JF - American Journal of Physiology - Cell Physiology

SN - 0363-6143

IS - 1 Pt 1

ER -