Connection of Smooth Muscle Cells to Elastic Lamellae in Aorta of Spontaneously Hypertensive Rats
| Autor: | Y. Bezie, Giorgio Gabella, Patrick Lacolley, Stéphane Laurent |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Male
Cytoplasm Muscle Smooth Vascular Extracellular matrix In vivo Rats Inbred SHR medicine.artery Internal Medicine medicine Animals Myocyte Aorta Abdominal Rats Wistar Organelles Aorta biology business.industry Histological Techniques Abdominal aorta Anatomy musculoskeletal system medicine.disease Adaptation Physiological Biomechanical Phenomena Elastin Extracellular Matrix Rats Microscopy Electron Blood pressure Hypertension cardiovascular system biology.protein Arterial stiffness business |
| Zdroj: | Hypertension. 32:166-169 |
| ISSN: | 1524-4563 0194-911X |
| DOI: | 10.1161/01.hyp.32.1.166 |
| Popis: | Abstract —We have recently demonstrated that in large arteries of spontaneously hypertensive rats (SHR), there is no increase of stiffness despite the increase in wall thickness, a sign of mechanical adaptation of the arterial wall to the higher level of stress. Because the dense plaques of smooth muscle are a major site of anchorage between the muscle cells and extracellular matrix, we determined by electron microscopy the distribution of dense plaques and their connections to elastic lamellae in the abdominal aorta of 1-year-old SHR and control Wistar rats. In vivo echo-tracking measurement of aortic distensibility and elastic modulus indicates a reduction of arterial stiffness in SHR compared with Wistar rats when they are studied over a common range of blood pressure. The media thickness to body weight ratio was higher in SHR than in Wistar rats. In the media, the percentage of sectional area occupied by extracellular matrix was not different between Wistar rats and SHR. The average number of dense plaques per muscle cell was not different between Wistar rats and SHR. However, the percentage of cell surface occupied by dense plaques was increased in SHR, and the percentage of cell surface connected to the elastic lamellae was twice as high in SHR compared with Wistar rats (9.4±1.5% versus 3.8±1.1%). These results suggest that the elastin network plays a major role in the mechanical adaptation of the arterial wall in SHR, not through variations of its total amount but through variations of the extent of anchorage to the muscle cells. |
| Databáze: | OpenAIRE |
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