Reduced cytosolic free Na+ concentration in intact platelets of essential hypertensives.
OBJECTIVE
The role of intracellular Na+ concentration in the pathogenesis of essential hypertension is a point of considerable discussion.


METHODS
Since the novel fluorescent dye technique offers the possibility of measuring cytosolic free Na+ concentration in intact living cells, the role of Na+ was reinvestigated in resting and stimulated human platelets.


METHODS
Cytosolic free Na+ concentration was measured in intact blood platelets of 20 essential hypertensive patients and 21 age- and sex-matched normotensive control subjects using the fluorescent dye Na(+)-binding benzofuran isophthalate.


RESULTS
Cytosolic free Na+ concentration was significantly reduced in hypertensives compared with normotensives. Inhibition of Na+,K(+)-adenosine triphosphatase by ouabain elevated cytosolic free Na+ concentration in hypertensives and normotensives in a similar way. Addition of thrombin increased cytosolic free Na+ concentration both in hypertensives and normotensives.


CONCLUSIONS
Previous concepts concerning the role of Na+ in the pathogenesis of essential hypertension based upon measurements in destructed cells need to be reinvestigarted using new techniques in living cells.
Tepel
M
M
Medizinische Universität-Poliklinik, Münster, Germany.
Bauer
S
S
Husseini
S
S
Zidek
W
W
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001792:Blood Platelets / Q000378:metabolism*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000209:etiology; D017136:Ion Transport; D008297:Male; D008875:Middle Aged; D012964:Sodium / Q000097:blood*
D012964:Sodium