Functional Effects of Cromakalim on Aortic Tissue in STZ-Diabetic Rats: Impact of Insulin Treatment
1Department of Pharmacology, School of Medicine, Istanbul Atlas University, Istanbul, Turkey.
Introduction:
K+ channels play a key role in the development of the vasodilation response, which is compromised in diabetes.
Methods:
In this study, the effects of the potassium channel activator cromakalim on aortic function were investigated in streptozotocin (STZ)-diabetic rats at short (1 week), medium (8 weeks), and long-term (14 weeks) durations, including a group treated with insulin for 14 weeks.
Results:
Compared with the control group, cromakalim-induced concentration-dependent vasodilation was reduced in the aortas of 8 and 14-week streptozotocin-diabetic rats (p < 0.05). Daily insulin treatment during the long-term (14 weeks) durations normalized the vasodilation response to cromakalim in the aortas of 14-week streptozotocin-diabetic rats.
Discussion:
Studies with chromacalim on diabetic rat aortic K+ channels are limited. Dose-dependent chromacalim-induced vasodilation was investigated in 8- and 12-week STZ-diabetic rat aortas and was found to be reduced. The impaired vasodilation responses were improved in the STZ-- diabetic group with chronic insulin treatment. The results of these studies were similar to those of our study.
Conclusion:
These findings indicate that potassium channel activity and vascular vasodilation ability decrease in the aortas of streptozotocin-diabetic rats depending on the duration of diabetes. In contrast, potassium channel activity and vascular vasodilation ability return to normal with insulin treatment in 14-week streptozotocin-diabetic aortas.
Insights
Potassium channel activity and vasodilation are reduced in diabetic rat aortas over time. Insulin treatment restored normal function in long-term diabetic rats, highlighting the importance of potassium channels in diabetes.
Area of Science:
- Cardiovascular Physiology
- Endocrinology
- Pharmacology
Background:
- Potassium (K+) channels are crucial for vasodilation.
- Diabetes mellitus impairs vascular function, including vasodilation.
- The role of K+ channels in diabetic vascular dysfunction requires further investigation.
Purpose of the Study:
- To investigate the impact of diabetes duration on aortic function.
- To assess the effect of a potassium channel activator, cromakalim, on vasodilation in diabetic rat aortas.
- To evaluate the therapeutic potential of insulin in restoring vascular function.
Main Methods:
- Streptozotocin (STZ)-induced diabetes in rats.
- Assessment of aortic vasodilation in response to cromakalim at 1, 8, and 14 weeks post-STZ induction.
- Evaluation of daily insulin treatment for 14 weeks in diabetic rats.
Main Results:
- Cromakalim-induced vasodilation was significantly reduced in aortas of rats at 8 and 14 weeks of diabetes.
- The duration of diabetes correlated with the degree of impaired vasodilation.
- Chronic insulin treatment normalized the vasodilation response to cromakalim in long-term diabetic rats.
Conclusions:
- Diabetes duration progressively impairs aortic vasodilation mediated by potassium channels.
- Insulin therapy effectively reverses diabetes-induced deficits in vascular function.
- Targeting potassium channels may offer therapeutic strategies for diabetic vascular complications.
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