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Ultrastructural changes in mesenteric arteries from spontaneously hypertensive rats. A morphometric study.
Blood Vessels
|January 1, 1983
Summary
Hypertension in spontaneously hypertensive rats (SHR) involves thickening of muscular and arteriolar mesenteric arteries. This is due to smooth muscle cell hyperplasia and hypertrophy, contributing to elevated blood pressure.
Area of Science:
- Vascular biology
- Cardiovascular research
- Hypertension mechanisms
Background:
- Spontaneously hypertensive rats (SHR) are a widely used model for studying human hypertension.
- Understanding arterial structural changes in SHR is crucial for identifying therapeutic targets.
Purpose of the Study:
- To investigate the detailed morphometric changes in mesenteric arteries of SHR compared to normotensive Wistar-Kyoto rats (WKY).
- To elucidate the cellular and structural contributions to arterial wall thickening in hypertension.
Main Methods:
- Electron microscopy was used for high-resolution morphometric analysis.
- Three types of mesenteric arteries (elastic, muscular, arteriolar) were examined in 10-12 week old SHR and WKY rats.
Main Results:
- Vessel wall thickening was observed in muscular and arteriolar arteries of SHR, primarily due to media hypertrophy.
- Specific changes included endothelial cell hypertrophy, widened subendothelial space, increased internal elastic lamina (IEL) volume, and smooth muscle cell (SMC) hyperplasia/hypertrophy.
- Increased elastin content and nerve density were noted in SHR muscular and arteriolar vessels, with no change in collagen.
Conclusions:
- Hypertension in SHR is associated with significant structural remodeling of muscular and arteriolar mesenteric arteries.
- SMC hyperplasia and hypertrophy are key contributors to arterial wall thickening and may be linked to elevated blood pressure.