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Changes in superoxide dismutase mRNA expression by streptozotocin‐induced diabetes
Author(s) -
Kamata Katsuo,
Kobayashi Tsuneo
Publication year - 1996
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1996.tb15712.x
Subject(s) - superoxide dismutase , streptozotocin , diabetes mellitus , endocrinology , medicine , messenger rna , chemistry , biology , biochemistry , oxidative stress , gene
1 Experiments were designed to investigate the involvement of superoxide anions in the attenuated endothelium‐dependent relaxation of the rat aorta from streptozotocin (STZ)‐induced diabetic rats. 2 The endothelium‐dependent relaxation responses to acetylcholine (ACh, 10 −7 m ) in helical strips of the aorta precontracted with noradrenaline (NA, 5 × 10 −8 ∼3 × 10 −7 m ) were significantly decreased in STZ‐induced diabetic rats. The recovery phase of the relaxation after single administration of ACh in the STZ‐induced diabetic rats was more rapid than those in control vessels. 3 Preincubation of aortic strips with superoxide dismutase (SOD, 60 u ml −1 ) normalized the recovery phase of the relaxation of diabetic aorta after single administration of ACh, whereas catalase (150 u ml −1 ) or indomethacin (10 −5 m ) had no effects on the relaxation. 4 SOD (180 u ml −1 ) caused relaxation in NA precontracted aortic strips and the degree of the SOD‐induced relaxation was significantly greater in diabetic aorta as compared with age‐matched control vessels. 5 When the changes in mRNA expressions of Mn‐SOD or Cu‐Zn‐SOD were observed, Mn‐SOD mRNA expression was markedly decreased, and Cu‐Zn‐SOD was slightly decreased in diabetic aorta. 6 These results suggest that the rapid destruction of NO by superoxide anions may occur in the STZ‐induced diabetic rats, and this may be due to a decrease in mRNA expression of Mn‐SOD or Cu‐Zn‐SOD.