title: Antioxidant treatment may protect pancreatic beta cells through the attenuation of islet fibrosis in an animal model of type 2 diabetes.
abstract: Islet fibrosis could be important in the progression of pancreatic beta cell failure in type 2 diabetes. It is known that oxidative stress is involved in the pancreatic fibrosis through the activation of pancreatic stellate cells. However, no study has investigated the in vivo effects of antioxidants on islet fibrogenesis in type 2 diabetes. In this study, antioxidants (taurine or tempol) were administered in drinking water to Otsuka Long-Evans Tokushima Fatty rats, an animal model of type 2 diabetes, for 16 weeks. An intraperitoneal glucose tolerance test revealed that the blood glucose levels after the glucose injection were decreased by the antioxidants. The insulin secretion after the glucose injection, which was markedly reduced in the rats, was also restored by the antioxidants. Beta cell mass and pancreatic insulin content were greater in the rats treated with the antioxidants than in the untreated rats. Beta cell apoptosis was attenuated in the rats by the antioxidants. Finally, islet fibrosis and the activation of pancreatic stellate cells were markedly diminished in the rats by the antioxidants. Our data suggest that antioxidants may protect beta cells through the attenuation of both islet fibrosis and beta cell apoptosis in type 2 diabetes.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Esder
authors.initials: E
authors.lastname: Lee
authors.forename: Gyeong Ryul
authors.initials: GR
authors.lastname: Ryu
authors.forename: Seung-Hyun
authors.initials: SH
authors.lastname: Ko
authors.forename: Yu-Bae
authors.initials: YB
authors.lastname: Ahn
authors.forename: Kun-Ho
authors.initials: KH
authors.lastname: Yoon
authors.forename: Hunjoo
authors.initials: H
authors.lastname: Ha
authors.forename: Ki-Ho
authors.initials: KH
authors.lastname: Song
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage*; D017209:Apoptosis / Q000187:drug effects*; D001786:Blood Glucose / Q000032:analysis; D003497:Cyclic N-Oxides / Q000008:administration & dosage; D019610:Cytoprotection; D003921:Diabetes Mellitus, Experimental / Q000517:prevention & control*; D003924:Diabetes Mellitus, Type 2 / Q000517:prevention & control*; D005355:Fibrosis; D005951:Glucose Tolerance Test; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000187:drug effects* / Q000473:pathology*; D008297:Male; D051381:Rats; D020334:Rats, Inbred OLETF; D013113:Spin Labels; D013654:Taurine / Q000008:administration & dosage
chemical_list: D000975:Antioxidants; D001786:Blood Glucose; D003497:Cyclic N-Oxides; D007328:Insulin; D013113:Spin Labels; D013654:Taurine; C001803:tempol