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Effects of deoxycorticosterone on arterial wall properties in two-kidney rats
Abstract:
The contribution of deoxycorticosterone acetate (DOCA) and salt to arterial pressure and hypertension-related arterial wall changes was assessed in Wistar rats. One group of two-kidney DOCA-treated animals was given a high salt diet and another group a low salt diet. After 16 weeks of treatment, the animals on low salt intake did not exhibit a significant increase in arterial pressure compared with untreated controls, while pressure was significantly elevated in the high-salt group. Values for the latter group were not as high as values in one-kidney, high salt DOCA-treated animals. Segments of the carotid and tail arteries were used for mechanical and chemical studies. Data obtained using arteries from the low salt two-kidney DOCA group were not significantly different from those of untreated controls. A number of significant differences were found in the two high salt groups compared with the low salt group and untreated controls; these included cardiac hypertrophy, increased passive arterial stiffness, decreased connective tissue concentration and increased maximum force development in response to high potassium plus norepinephrine activation. Larger changes were found in one-kidney compared to two-kidney DOCA animals. Thus DOCA administration to two-kidney rats on high salt intake produces moderate arterial hypertension and hypertension-related arterial wall changes. On the other hand DOCA administration to two-kidney rats on low salt intake does not produce an increase in arterial pressure nor altered arterial wall properties. These results suggest that DOCA in the absence of salt excess does not elevate arterial pressure or produce arterial wall changes.(ABSTRACT TRUNCATED AT 250 WORDS)
Insights
Deoxycorticosterone acetate (DOCA) and high salt intake significantly increase arterial pressure and cause arterial wall changes in rats. However, DOCA alone without excess salt does not elevate blood pressure or alter arterial properties.
Area of Science:
- Cardiovascular Physiology
- Renal Physiology
- Hypertension Research
Background:
- Deoxycorticosterone acetate (DOCA) is a steroid hormone involved in regulating blood pressure and electrolyte balance.
- Salt intake is a known factor contributing to hypertension development.
- Understanding the interplay between DOCA and salt is crucial for hypertension research.
Purpose of the Study:
- To investigate the independent and combined effects of DOCA and salt on arterial pressure.
- To assess DOCA and salt-induced changes in arterial wall properties.
- To determine the role of salt in mediating DOCA-induced hypertension and vascular alterations.
Main Methods:
- Wistar rats were administered DOCA with either a high or low salt diet for 16 weeks.
- Arterial pressure was monitored throughout the study period.
- Mechanical and chemical studies were performed on carotid and tail artery segments.
Main Results:
- High salt intake combined with DOCA significantly elevated arterial pressure and induced cardiac hypertrophy.
- Arterial stiffness increased, connective tissue concentration decreased, and force development was enhanced in high salt groups.
- DOCA administration with a low salt diet did not result in significant increases in arterial pressure or altered arterial wall properties.
- One-kidney DOCA-treated animals exhibited more pronounced changes than two-kidney DOCA-treated animals.
Conclusions:
- DOCA administration exacerbates arterial hypertension and vascular remodeling in the presence of high salt intake.
- DOCA alone, without salt excess, does not appear to elevate arterial pressure or alter arterial wall properties.
- Salt intake is a critical determinant in the development of DOCA-induced hypertension and associated vascular changes.