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Mesenteric vascular reactivity in dexamethasone-treated hypertensive rats
Hypertension (Dallas, Tex. : 1979)
|September 1, 1985
Summary
Long-term dexamethasone treatment in rats selectively increases mesenteric vascular reactivity to arginine vasopressin, independent of prostaglandin synthesis. This enhanced response may contribute to glucocorticoid-induced hypertension.
Area of Science:
- Pharmacology
- Cardiovascular Physiology
- Endocrinology
Background:
- Glucocorticoids, like dexamethasone, can induce hypertension.
- Vascular reactivity and prostaglandin synthesis are crucial in blood pressure regulation.
Purpose of the Study:
- To investigate how dexamethasone affects mesenteric vascular reactivity to vasoactive agents.
- To explore the role of prostaglandins in dexamethasone-induced changes in vascular tone.
Main Methods:
- Rats were treated with dexamethasone for 1 or 14 days.
- Superior mesenteric arteries were isolated and perfused.
- Vascular responses to norepinephrine, angiotensin II, and arginine vasopressin were measured.
- Prostaglandin output was quantified.
Main Results:
- Dexamethasone treatment (14 days) enhanced vasoconstriction to arginine vasopressin but not norepinephrine or angiotensin II.
- Prostaglandin output (basal and stimulated) was reduced in dexamethasone-treated rats.
- Enhanced arginine vasopressin response was independent of altered prostaglandin synthesis.
Conclusions:
- Long-term dexamethasone exposure selectively increases mesenteric vascular sensitivity to arginine vasopressin.
- This heightened reactivity, independent of prostaglandins, may play a role in glucocorticoid-induced hypertension.