Membrane microviscosity, blood pressure and cytosolic pH in Dahl rats
| Autor: | Josef Zicha, Marie-Aude Devynck, Jaroslav Kuneš, Kim Hanh Le Quan Sang |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Blood Platelets
Male medicine.medical_specialty Sodium-Hydrogen Exchangers Physiology Blood Pressure Microviscosity chemistry.chemical_compound Cytosol Internal medicine Internal Medicine medicine Animals Platelet Sodium Chloride Dietary Fluorescent Dyes Rats Inbred Dahl Cholesterol business.industry Erythrocyte Membrane technology industry and agriculture Hydrogen-Ion Concentration Blood Viscosity Animal Feed Lipids Rats Membrane Blood pressure Endocrinology chemistry Hypertension lipids (amino acids peptides and proteins) Cardiology and Cardiovascular Medicine Bacterial outer membrane business Diphenylhexatriene Fluorescence anisotropy Follow-Up Studies |
| Zdroj: | Journal of Hypertension. 17:785-792 |
| ISSN: | 0263-6352 |
| Popis: | Objective To determine the relationships between blood pressure, membrane microviscosity, plasma lipids and cytosolic pH in Dahl rats susceptible or resistant to salt hypertension. Design and methods Blood pressure, plasma triglycerides and total cholesterol, platelet cytosolic pH (pH i ) and the microviscosity of both outer membrane leaflet (TMA-DPH fluorescence anisotropy) and membrane lipid core (DPH fluorescence anisotropy) were studied in platelets and erythrocyte ghosts of Dahl salt-sensitive (SS/Jr) and salt-resistant (SR/Jr) rats fed either a low-salt diet (0.3% NaCI) until the age of 9, 15 or 24 weeks or a high-salt diet (4% NaCI) for 5 or 10 weeks after weaning. Results At low salt intake, DPH but not TMA-DPH anisotropy increased with age in platelets of SS/Jr rats. Chronic high salt intake was accompanied by an increase of DPH anisotropy in platelets but not in erythrocyte ghosts of SS/Jr rats. Platelet DPH anisotropy correlated positively with blood pressure of salt-loaded SS/Jr rats. Chronic high salt intake also reduced pH i in platelets, the regulation of which seemed to be related to the changes in TMA-DPH anisotropy. This especially concerns the thrombin-induced pH i rise which was inversely related to basal pH i , plasma lipids and TMA-DPH anisotropy. Altered membrane lipid composition might be the underlying mechanism because both membrane microviscosity and platelet pH i regulation were reported to correlate significantly with plasma triglycerides and/or cholesterol. Conclusions Platelets of salt hypertensive Dahl rats are characterized by an increased microviscosity of membrane lipid core which correlated positively with blood pressure. The major influence of plasma triglycerides on DPH anisotropy should be taken into consideration when investigating the links between membrane microviscosity and blood pressure. On the other hand, the changes in microviscosity of the outer membrane leaflet might be involved in pH i regulation (probably through control of the Na + /H + exchanger). |
| Databáze: | OpenAIRE |
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