Abstract
Amylin can evoke insulin resistance by antagonizing insulin in a non-competitive manner. Here, we investigated the glycogenolytic effect of amylin in isolated skeletal muscle and compared it to the effects of a calcitonin gene-related peptide (CGRP). Amylin alone had no statistically significant effect on glucose transport. However, amylin decreased insulin-stimulated glucose transport by about 30%. The involvement of cAMP could not be detected at the concentrations shown to promote glycogenolysis. Previously, it has been shown that increased glycogen synthase kinase 3 (GSK3) activity plays a role in insulin resistance. Here, the ratio of GSK3 α:β isoforms in rat soleus was found to be 1.2:1. We found that amylin increased GSK3α activity, which in turn led to increased phosphorylation of glycogen synthase and decreased glycogen synthesis de novo.
Original language | English (US) |
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Pages (from-to) | 2119-2125 |
Number of pages | 7 |
Journal | Peptides |
Volume | 25 |
Issue number | 12 |
DOIs | |
State | Published - Dec 1 2004 |
Keywords
- 2-deoxy-glucose
- cAMP
- CGRP
- Glycogen
ASJC Scopus subject areas
- Biochemistry
- Endocrinology
- Physiology
- Cellular and Molecular Neuroscience