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Calcium and vascular smooth muscle membrane in hypertension
Insights
Altered calcium handling is a primary membrane defect in hypertension, leading to increased vascular smooth muscle sensitivity and elevated arterial pressure. This impacts total peripheral resistance.
Area of Science:
- Cardiovascular Research
- Membrane Physiology
- Hypertension Pathophysiology
Background:
- Hypertension research focuses on vascular changes increasing total peripheral resistance and arterial pressure.
- Altered calcium handling is increasingly implicated in hypertension.
Purpose of the Study:
- To survey evidence suggesting altered calcium handling as a primary membrane defect in hypertension.
- To explore the link between calcium handling, membrane permeability, and vascular reactivity.
Main Methods:
- Review of recent evidence on calcium binding in hypertensive animal tissues.
- Analysis of membrane permeability to cations in hypertension.
- Assessment of vascular smooth muscle sensitivity to vasoconstrictors.
Main Results:
- Hypertensive animal tissues show reduced membrane calcium binding capacity.
- This defect increases membrane permeability to monovalent and divalent cations.
- Increased cation permeability enhances vascular smooth muscle sensitivity to vasoconstrictors.
Conclusions:
- Altered calcium handling represents a primary membrane defect in hypertension.
- This defect contributes significantly to elevated arterial pressure and vascular dysfunction.
Abstract:
A major focus of past and recent research in hypertension has been on the characterization of the nature of the vasculature changes which lead to the observed increase in total peripheral resistance responsible for the elevation of arterial pressure. Here we survey recent evidence which suggests that altered handling of calcium is a primary membrane defect in hypertension. Evidence for the primacy of this defect is provided by studies demonstrating a reduced ability of the membrane to bind calcium in diverse tissues from hypertensive animals. The reduced calcium binding ability appears to be responsible for a greater membrane permeability to monovalent and divalent cations. This greater permeability contributes to the increased sensitivity to vasoconstrictor stimuli of vascular smooth muscle in hypertension.