Changes in glucose transport and protein kinase Cβ 2 in rat skeletal muscle induced by hyperglycaemia
| Autor: | A. Soler, Jorge Rincon, Lorraine A. Nolte, Juleen R. Zierath, Yuichi Kawano, Harriet Wallberg-Henriksson, Jeffrey W. Ryder |
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| Rok vydání: | 1999 |
| Předmět: |
Male
Snf3 medicine.medical_specialty Monosaccharide Transport Proteins Endocrinology Diabetes and Metabolism Muscle Proteins Protein Kinase C beta In Vitro Techniques Biology Internal medicine Internal Medicine medicine Animals Insulin Rats Wistar Muscle Skeletal Protein kinase A Protein Kinase C Protein kinase C Hexose transport Glucose Transporter Type 1 Glucose Transporter Type 4 Cell Membrane Glucose transporter Skeletal muscle Rats Isoenzymes Kinetics Glucose Endocrinology medicine.anatomical_structure Biochemistry Hyperglycemia 3-O-Methylglucose |
| Zdroj: | Diabetologia. 42:1071-1079 |
| ISSN: | 1432-0428 0012-186X |
| DOI: | 10.1007/s001250051273 |
| Popis: | Aims/hypothesis. We have previously reported that hyperglycaemia activates glucose transport in skeletal muscle by a Ca2+-dependent pathway, which is distinct from the insulin-signalling pathway. The aim of this study was to explain the signalling mechanism by which hyperglycaemia autoregulates glucose transport in skeletal muscle. Methods. Isolated rat soleus muscle was incubated in the presence of various concentrations of glucose or 3-O-methylglucose and protein kinase C and phospholipase C inhibitors. Glucose transport activity, cell surface glucose transporter 1 and glucose transporter 4 content and protein kinase C translocation was determined. Results. High concentrations of 3-O-methylglucose led to a concentration-dependent increase in [3H]-3-O-methylglucose transport in soleus muscle. Dantrolene, an inhibitor of Ca2+ released from the sarcoplasmic reticulum, decreased the Vmax and the Km of the concentration-response curve. Protein kinase C inhibitors (H-7 and GF109203X) inhibited the stimulatory effect of high glucose concentrations on hexose transport, whereas glucose transport stimulated by insulin was unchanged. Incubation of muscle with glucose (25 mmol/l) and 3-O-methylglucose (25 mmol/l) led to a three fold gain in protein kinase Cβ 2 in the total membrane fraction, whereas membrane content of protein kinase Cα, β 1, δ, ɛ and ϑ were unchanged. A short-term increase in the extracellular glucose concentration did not change cell surface recruitment of glucose transporter 1 or glucose transporter 4, as assessed by exofacial photolabelling with [3H]-ATB-BMPA bis-mannose. Conclusion/interpretation. Protein kinase Cβ 2 is involved in a glucose-sensitive, Ca2+-dependent signalling pathway, which is possibly involved in the regulation of glucose transport in skeletal muscle. This glucose-dependent increase in 3-0-methylglucose transport is independent of glucose transporter 4 and glucose transporter 1 translocation to the plasma membrane and may involve modifications of cell surface glucose transporter activity. [Diabetologia (1999) 42: 1071–1079] |
| Databáze: | OpenAIRE |
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