Research Background and Purpose: The number of diabetic patients is rapidly increasing, making it crucial to find methods to prevent diabetic retinopathy (DR), a leading cause of blindness. We investigated the effects...Research Background and Purpose: The number of diabetic patients is rapidly increasing, making it crucial to find methods to prevent diabetic retinopathy (DR), a leading cause of blindness. We investigated the effects of prophylactic pattern scanning laser retinal photocoagulation on DR development in Spontaneously Diabetic Torii (SDT) fatty rats as a new prevention approach. Methods: Photocoagulation was applied to the right eyes of 8-week-old Spontaneously Diabetic Torii (SDT) fatty rats, with the left eyes serving as untreated controls. Electroretinography at 9 and 39 weeks of age and pathological examinations, including immunohistochemistry for vascular endothelial growth factor and glial fibrillary acidic protein at 24 and 40 weeks of age, were performed on both eyes. Results: There were no significant differences in amplitude and prolongation of the OP waves between the right and left eyes in SDT fatty rats at 39 weeks of age. Similarly, no significant differences in pathology and immunohistochemistry were observed between the right and left eyes in SDT fatty rats at 24 and 40 weeks of age. Conclusion: Prophylactic pattern scanning retinal laser photocoagulation did not affect the development of diabetic retinopathy in SDT fatty rats.展开更多
The number of diabetic patients has recently been increasing all over the world together with lifestyle changes including sedentary life and high-calorie diet intake, and as a result the increase in these suffering fr...The number of diabetic patients has recently been increasing all over the world together with lifestyle changes including sedentary life and high-calorie diet intake, and as a result the increase in these suffering from diabetes mellitus has become a global issue. Diabetic animal models play a key role in bettering our understanding of the pathophysiology of diabetes and in developing new therapies for the disease. Diabetes is classified into two types, type 1 and type 2, and type 2 diabetes is chiefly caused by a depletion of insulin secretion in the pancreas and insulin resistance in peripheral tissues. The Goto-Kakizaki (GK) rat and the Spontaneously Diabetic Torii (SDT) rat are genetic non-obese type 2 diabetic models, and the both rats are considered to be suitable models for investigating the etiology of the depletion of insulin secretion and impaired glucose tolerance. In this review, we overviewed the outline of pathophysiological features in GK rats and SDT rats, including biological parameters and pharmacological responses.展开更多
The Spontaneously Diabetic Torii (SDT) rat is a nonobese type 2 diabetic model, showing the overt hyperglycemia after about 16 weeks of age. In this study, we investigated the protein tyrosine phosphatase (PTPase) act...The Spontaneously Diabetic Torii (SDT) rat is a nonobese type 2 diabetic model, showing the overt hyperglycemia after about 16 weeks of age. In this study, we investigated the protein tyrosine phosphatase (PTPase) activities in insulin-sensitive tissues in SDT rats. PTPase activities in the liver, muscle, and fat were examined at 8 weeks (pre-diabetes), 16 weeks (onset-diabetes), and 24 weeks (diabetes). SDT rats showed glucose intolerance at 8 weeks and hyperglycemia after 16 weeks. The PTPase activities in fat increased at 8 weeks and the increase was sustained to 24 weeks. In the liver, PTPase activities increased only at 24 weeks. On the other hand, the PTPase activities in muscle did not change. The increase of PTPase activity in fat might be related to progression of glucose intolerance and diabetes in SDT rats.展开更多
文摘Research Background and Purpose: The number of diabetic patients is rapidly increasing, making it crucial to find methods to prevent diabetic retinopathy (DR), a leading cause of blindness. We investigated the effects of prophylactic pattern scanning laser retinal photocoagulation on DR development in Spontaneously Diabetic Torii (SDT) fatty rats as a new prevention approach. Methods: Photocoagulation was applied to the right eyes of 8-week-old Spontaneously Diabetic Torii (SDT) fatty rats, with the left eyes serving as untreated controls. Electroretinography at 9 and 39 weeks of age and pathological examinations, including immunohistochemistry for vascular endothelial growth factor and glial fibrillary acidic protein at 24 and 40 weeks of age, were performed on both eyes. Results: There were no significant differences in amplitude and prolongation of the OP waves between the right and left eyes in SDT fatty rats at 39 weeks of age. Similarly, no significant differences in pathology and immunohistochemistry were observed between the right and left eyes in SDT fatty rats at 24 and 40 weeks of age. Conclusion: Prophylactic pattern scanning retinal laser photocoagulation did not affect the development of diabetic retinopathy in SDT fatty rats.
文摘The number of diabetic patients has recently been increasing all over the world together with lifestyle changes including sedentary life and high-calorie diet intake, and as a result the increase in these suffering from diabetes mellitus has become a global issue. Diabetic animal models play a key role in bettering our understanding of the pathophysiology of diabetes and in developing new therapies for the disease. Diabetes is classified into two types, type 1 and type 2, and type 2 diabetes is chiefly caused by a depletion of insulin secretion in the pancreas and insulin resistance in peripheral tissues. The Goto-Kakizaki (GK) rat and the Spontaneously Diabetic Torii (SDT) rat are genetic non-obese type 2 diabetic models, and the both rats are considered to be suitable models for investigating the etiology of the depletion of insulin secretion and impaired glucose tolerance. In this review, we overviewed the outline of pathophysiological features in GK rats and SDT rats, including biological parameters and pharmacological responses.
文摘The Spontaneously Diabetic Torii (SDT) rat is a nonobese type 2 diabetic model, showing the overt hyperglycemia after about 16 weeks of age. In this study, we investigated the protein tyrosine phosphatase (PTPase) activities in insulin-sensitive tissues in SDT rats. PTPase activities in the liver, muscle, and fat were examined at 8 weeks (pre-diabetes), 16 weeks (onset-diabetes), and 24 weeks (diabetes). SDT rats showed glucose intolerance at 8 weeks and hyperglycemia after 16 weeks. The PTPase activities in fat increased at 8 weeks and the increase was sustained to 24 weeks. In the liver, PTPase activities increased only at 24 weeks. On the other hand, the PTPase activities in muscle did not change. The increase of PTPase activity in fat might be related to progression of glucose intolerance and diabetes in SDT rats.
