Regulation of rat Na+/Pi cotransporter-1 gene expression: the roles of glucose and insulin
| Autor: | P. Ren, M. Onwochei, R. J. Ruch, Zijian Xie, H. Li |
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| Rok vydání: | 1996 |
| Předmět: |
Male
medicine.medical_specialty Physiology Endocrinology Diabetes and Metabolism medicine.medical_treatment Carbohydrate metabolism Biology Kidney Glucagon Diabetes Mellitus Experimental Rats Sprague-Dawley Downregulation and upregulation Physiology (medical) Internal medicine medicine Animals Insulin Symporters Sodium-Phosphate Cotransporter Proteins Type III Sodium-Phosphate Cotransporter Proteins Metabolism Fasting Rats Insulin receptor Endocrinology Glucose Gene Expression Regulation Liver biology.protein Cotransporter Carrier Proteins Homeostasis |
| Zdroj: | The American journal of physiology. 271(6 Pt 1) |
| ISSN: | 0002-9513 |
| Popis: | Cytosolic inorganic phosphate (P(i)) is important for glucose metabolism. It plays a role in homeostatic regulation of glucose by insulin and glucagon. Recently, we isolated two cDNA clones for rat Na+/P(i) cotransporter-1 (rNaPi-1) and demonstrated that they are expressed primarily in the rat liver and kidney. We now report that the expression of rNaPi-1 in these tissues is regulated by fasting and streptozotocin-induced diabetes. Using rat hepatocytes in primary culture, we also demonstrate that glucose and insulin upregulate rNaPi-1 expression, whereas glucagon and elevated intracellular adenosine 3',5'-cyclic monophosphate levels downregulate its expression. Because 2-deoxyglucose exhibits no effect on rNaPi-1 gene expression, we suggest that some metabolite accumulated during glucose metabolism may be responsible for the effects of glucose and insulin on rNaPi-1 gene expression. Our data also reveal that other known Na+/P(i) cotransporter genes, NaPi-2 and Ram-1 (a receptor for amphotropic murine retrovirus), are not regulated by insulin and glucose. It is therefore proposed that various subtypes of Na+/P(i) cotransporters are differentially regulated and that each subtype may be involved in a specific cellular function, rNaPi-1 may be responsible for Pi uptake by liver and kidney for glucose metabolism, whereas NaPi-2 may play a key role in P(i) reabsorption in the kidney. |
| Databáze: | OpenAIRE |
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