European Journal of Clinical Pharmacology

, Volume 43, Issue 6, pp 635–638

The sensitivity of human blood platelets to the aggregating agent ADP during different dietary sodium intakes in healthy men

  • I. F. Gow
  • M. Dockrell
  • C. R. W. Edwards
  • A. Elder
  • J. Grieve
  • G. Kane
  • P. L. Padfield
  • C. J. Waugh
  • B. C. Williams
Originals

DOI: 10.1007/BF02284963

Cite this article as:
Gow, I.F., Dockrell, M., Edwards, C.R.W. et al. Eur J Clin Pharmacol (1992) 43: 635. doi:10.1007/BF02284963

Summary

We have investigated the effect of varying sodium intake on the renin-angiotensin system, ADP-induced patelet aggregationin vitro, and blood 5-HT concentrations in 9 male volunteers.

Systolic blood pressure was slightly reduced during a low sodium diet, whereas the diastolic pressure remained unchanged. Plasma renin activity and aldosterone concentration both fell significantly when sodium intake was increased; plasma angiotensin lI concentraion also fell, but not significantly.

There was a significant fall in haematocrit after an increased sodium intake, but there was no change in the whole-blood platelet count after correcting for this. There were no significant changes in either total (i. e. PRP) or platelet 5-HT concentrations.

The extent of platelet aggregation induced by 5 and 20 μmol · 1−1 of ADP increased significantly when dietary sodium intake was increased. When compared with low or normal sodium intakes, lower concentrations of ADP were required to produce 50% of maximum aggregation after a high sodium intake. The 5-HT2, receptor antagonist ketanserin (1 μmol · 1−1in vitro) reduced the extent of aggregation induced by 5 μmol · 1−1 ADP after the volunteers had taken a high sodium diet, whereas the angiotensin 11 receptor anatgonist saralasin (1 nmol-1−1) increased the rate of aggregation after the low sodium diet.

Thus, during a high sodium intake, human platelets become more sensitive to the aggregating agent ADP It is possible that this effect is mediatedvia platelet 5-HT2 receptors, since ketanserin abolished the increase in salt-induced aggregation seen with 5 μmol · 1−1 ADP.

Key words

Platelet aggregation, Ketanserinsodium diet, pharma renin activity, platelet 5-HT2 receptor

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • I. F. Gow
    • 1
    • 2
  • M. Dockrell
    • 1
  • C. R. W. Edwards
    • 1
  • A. Elder
    • 1
  • J. Grieve
    • 1
  • G. Kane
    • 1
  • P. L. Padfield
    • 1
  • C. J. Waugh
    • 1
  • B. C. Williams
    • 1
  1. 1.Departments of Medicine and CardiologyWestern General HospitalEdinburghUK
  2. 2.Department of PhysiologyMedical SchoolEdinburghUK