Yoshikawa H, Tajiri Y, Sako Y, Hashimato T, Umeda F, Nawata H. Glucosamine-induced beta-cell dysfunction: a possible involvement of glucokinase or glucose-transporter type 2.
Pancreas 2002;
24:228-34. [PMID:
11893929 DOI:
10.1097/00006676-200204000-00004]
[Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION
The mechanism for beta-cell dysfunction induced by glucosamine has not yet fully been investigated previously.
AIM
To investigate the effects of glucosamine on insulin release or gene expression related to glucose metabolism in rat islets cultured with glucosamine for 24 hours.
METHODOLOGY
After islets were cultured with glucosamine or diazoxide, we measured glucose- or arginine-induced insulin release by using radioimmunoassay (RIA) and gene expressions by semiquantitative polymerase/chain reaction.
RESULTS
Coculture with glucosamine inhibited 27 mmol/L glucose-induced insulin release with no effects on 20 mmol/L arginine-induced insulin release. Coculture with diazoxide did not restore the impaired glucose-induced insulin release. In glucosamine-cultured islets, glucose-transporter type 2 or glucokinase mRNA expression decreased, whereas hexokinase mRNA increased. Phosphofructokinase-A, pyruvate dehydrogenase E1alpha, or pyruvate carboxylase mRNA was not affected by the addition of glucosamine. Pancreatic and duodenal homeobox-1, preproinsulin, or p21 (induced by oxidative stress) mRNA expression did not change, whereas uncoupling protein 2 mRNA, which plays an important role in thermogenesis, decreased in glucosamine-cultured islets.
CONCLUSION
These data imply that glucosamine impairs glucose-induced insulin release probably through the inhibition of glucose metabolism.
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