Related Experiment Video
Updated: Sep 28, 2026
A Protocol for Constructing a Rat Wound Model of Type 1 Diabetes
Published on: February 17, 2023
Attenuated arterial and venous constriction in conscious rats with streptozotocin-induced diabetes
Xing Cheng1, Susan W S Leung, Su L Lim
1Department of Pharmacology and Therapeutics, Faculty of Medicine, The University of British Columbia, Vancouver, Canada.
Abstract:
We examined if arterial or venous constriction is impaired in early diabetes. Dose-pressor and mean circulatory filling pressure (index of venous tone) response curves to noradrenaline and angiotensin II were constructed in four groups of conscious, instrumented, Wistar rats pretreated with streptozotocin (60 mg/kg i.v.) or vehicle at 2 weeks prior to the study. Rats with diabetes, relative to controls, had increased ED(50) (reduced potency) for the pressor (2.5-fold of control) and mean circulatory filling pressure (4.3-fold of control) response to noradrenaline, as well as reduced maximum pressor response (efficacy) to noradrenaline (diabetic, 74+/-8 mm Hg; control, 96+/-5 mm Hg). Diabetic rats also had reduced potency (ED(50), 5-fold of control) of the pressor response to angiotensin II; however, maximum pressor response and dose-mean circulatory filling pressure curve to angiotensin II were similar in both groups. Therefore, arterial and venous constrictions are impaired at an early phase of type I diabetes.
Insights
Early diabetes impairs both arterial and venous constriction. This study in Wistar rats shows reduced responses to noradrenaline and angiotensin II, indicating compromised vascular tone in diabetic subjects.
Area of Science:
- Cardiovascular Physiology
- Endocrinology
- Pharmacology
Background:
- Diabetes mellitus is a complex metabolic disorder with significant cardiovascular implications.
- Vascular dysfunction, including impaired arterial and venous tone, is a hallmark of diabetes.
- Early detection and understanding of vascular changes are crucial for managing diabetic complications.
Purpose of the Study:
- To investigate whether arterial and venous constriction are impaired in the early stages of type 1 diabetes.
- To quantify the effects of diabetes on the pressor and venous tone responses to vasoconstrictive agents.
Main Methods:
- Utilized streptozotocin-induced diabetes model in conscious, instrumented Wistar rats.
- Constructed dose-response curves for noradrenaline and angiotensin II to assess pressor (arterial constriction) and mean circulatory filling pressure (venous tone) responses.
- Compared responses between diabetic rats and control groups at 2 weeks post-induction.
Main Results:
- Diabetic rats exhibited significantly reduced potency (increased ED50) for both pressor and venous tone responses to noradrenaline.
- A decrease in the maximum pressor response (efficacy) to noradrenaline was observed in diabetic rats.
- Reduced potency was also noted for the pressor response to angiotensin II in diabetic rats, while venous tone responses remained similar.
Conclusions:
- Arterial and venous constrictions are demonstrably impaired during the early phase of type 1 diabetes.
- These findings highlight early-onset vascular dysfunction in diabetes, affecting responses to key vasoconstrictors.
- The study underscores the importance of addressing vascular tone abnormalities in the management of early diabetes.
Related Concept Videos
01:28Diabetic Nephropathy
01:27Diabetic Retinopathy