| Autor: |
Wahren J; Department of Surgical Sciences, Section of Clinical Physiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden. john.wahren@creativepeptides.se, Shafqat J, Johansson J, Chibalin A, Ekberg K, Jörnvall H |
| Jazyk: |
angličtina |
| Zdroj: |
Experimental diabesity research [Exp Diabesity Res] 2004 Jan-Mar; Vol. 5 (1), pp. 15-23. |
| DOI: |
10.1080/15438600490424479 |
| Abstrakt: |
New results present C-peptide as a biologically active peptide hormone in its own right. Although C-peptide is formed from proinsulin and cosecreted with insulin, it is a separate entity with biochemical and physiological characteristics that differ from those of insulin. There is direct evidence of stereospecific binding of C-peptide to a cell surface receptor, which is different from those for insulin and other related hormones. The C-peptide binding site is most likely a G-protein-coupled receptor. The association constant for C-peptide binding is approximately 3 x 10(9) M(-1). Saturation of the binding occurs already at a concentration of about 1 nM, which explains why C-peptide effects are not observed in healthy subjects. Binding of C-peptide results in activation of Ca2+ and MAPK-dependent pathways and stimulation of Na+,K(+)-ATPase and eNOS activities. The latter 2 enzymes are both deficient in several tissues in type 1 diabetes. There is some evidence that C-peptide, and insulin may interact synergistically on the insulin signaling pathway. Clinical evidence suggests that replacement of C-peptide, together with regular insulin therapy, may be beneficial in patients with type 1 diabetes and serve to retard or prevent the development of long-term complications. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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