C-Peptide effects on renal physiology and diabetes.
The C-peptide of proinsulin is important for the biosynthesis of insulin and has for a long time been considered to be biologically inert. Animal studies have shown that some of the renal effects of the C-peptide may in part be explained by its ability to stimulate the Na,K-ATPase activity. Precisely, the C-peptide reduces diabetes-induced glomerular hyperfiltration both in animals and humans, therefore, resulting in regression of fibrosis. The tubular function is also concerned as diabetic animals supplemented with C-peptide exhibit better renal function resulting in reduced urinary sodium waste and protein excretion together with the reduction of the diabetes-induced glomerular hyperfiltration. The tubular effectors of C-peptide were considered to be tubule transporters, but recent studies have shown that biochemical pathways involving cellular kinases and inflammatory pathways may also be important. The matter theory concerning the C-peptide effects is a metabolic one involving the effects of the C-peptide on lipidic metabolic status. This review concentrates on the most convincing data which indicate that the C-peptide is a biologically active hormone for renal physiology.
UPRES EA 21-93, Laboratoire de Diabétologie, Faculté de Médecine de Marseille, Université de la Méditerranée, 13385 Marseille Cedex 05, France.
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Khammar
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Raccah
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Tsimaratos
D000818:Animals; D002096:C-Peptide / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism / Q000503:physiopathology; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism / Q000503:physiopathology*; D003928:Diabetic Nephropathies / Q000378:metabolism / Q000503:physiopathology*; D005919:Glomerular Filtration Rate; D006801:Humans; D007249:Inflammation / Q000378:metabolism / Q000503:physiopathology; D007678:Kidney Glomerulus / Q000378:metabolism / Q000503:physiopathology*; D007684:Kidney Tubules / Q000378:metabolism / Q000503:physiopathology*; D050356:Lipid Metabolism; D015398:Signal Transduction; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
D002096:C-Peptide; D000254:Sodium-Potassium-Exchanging ATPase