Related Experiment Videos
Blood pressure inversely correlates with thrombin-evoked calcium rise in platelets
J P Gardner1, J H Cho, J H Skurnick
1Hypertension Research Center, UMDNJ-New Jersey Medical School, Newark 07103.
Insights
Peak thrombin-evoked cytosolic calcium in human platelets, measured in a calcium-containing medium, shows the strongest correlation with blood pressure, particularly diastolic pressure. This finding offers a more reliable platelet calcium parameter for blood pressure assessment.
Area of Science:
- Cardiovascular Physiology
- Human Physiology
- Biochemistry
Background:
- Previous research indicated a link between basal platelet cytosolic calcium and blood pressure, but recent studies yielded conflicting results.
- Variability in measurement methods may explain discrepancies in prior investigations.
- Understanding reliable platelet calcium parameters is crucial for cardiovascular health research.
Purpose of the Study:
- To identify platelet cytosolic calcium parameters with minimal variability and maximal correlation to blood pressure.
- To compare resting and stimulated platelet calcium levels in different media.
- To assess the relationship between various platelet calcium dynamics and both manual and automated blood pressure readings.
Main Methods:
- Seventeen healthy men were studied on three separate occasions over several weeks.
- Blood pressure was measured manually and via 24-hour ambulatory automated monitoring.
- Fura-2 loaded platelets were analyzed for basal, thrombin-evoked peak, and post-transient cytosolic calcium levels in both calcium-containing and calcium-free media.
Main Results:
- Peak thrombin-evoked cytosolic calcium in a calcium-containing medium exhibited the lowest coefficient of variation (10.1%).
- Basal cytosolic calcium showed no correlation with any blood pressure parameters.
- Peak thrombin-evoked cytosolic calcium in calcium medium demonstrated consistent negative correlations with blood pressure, stronger with diastolic than systolic, and comparable across daytime and nighttime automated readings.
Conclusions:
- Peak thrombin-evoked cytosolic calcium in a calcium-containing medium is the most reliable platelet calcium parameter for correlating with blood pressure.
- This specific platelet calcium measurement shows a stronger association with diastolic blood pressure.
- The findings suggest a refined approach to utilizing platelet calcium as a biomarker for hypertension research.
Abstract:
Earlier investigations showed a positive correlation between basal cytosolic free calcium in human platelets and blood pressure; however, recent studies have failed to show this relation. We undertook the present work to examine which platelet cytosolic calcium parameters (namely, cytosolic calcium in resting or stimulated states in calcium-containing and calcium-free media) present the least variability and best correlation with blood pressure. We studied 17 healthy white men on three different occasions separated by 1- and 4-week intervals. Their manual and ambulatory automated 24-hour blood pressure measurements were correlated with cytosolic calcium in resting and stimulated (thrombin-treated) fura 2-loaded platelets. The following cytosolic calcium parameters were measured in 1 mmol/L calcium and calcium-free media: basal cytosolic calcium, peak thrombin-evoked cytosolic calcium, and post-transient cytosolic calcium 5 minutes after thrombin treatment. The highest and lowest coefficients of variation were respectively shown by the basal cytosolic calcium (22.8%) and peak thrombin-evoked cytosolic calcium (10.1%) in calcium medium. Basal cytosolic calcium did not correlate with any of the blood pressure parameters. Of the cytosolic calcium parameters, peak thrombin-evoked cytosolic calcium in calcium medium demonstrated consistent (negative) correlations with blood pressure, with better correlations shown with diastolic than systolic blood pressure of both automated and manual blood pressure readings. Peak thrombin-evoked cytosolic calcium in calcium medium showed similar correlations with nighttime and daytime automated blood pressure measurements. There were no correlations between peak thrombin-evoked cytosolic calcium in calcium-free medium and blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)