Does cytosolic free calcium concentration in platelets reflect tone and structural changes of resistance vessels?
To investigate tone and vascular changes of resistance vessels as related to cytosolic free calcium concentration [( Ca2+]i) in platelets, we measured forearm vascular resistance and free calcium concentration in platelets from 10 essential hypertensives and 15 normotensives. The [Ca2+]i in platelets was significantly higher in essential hypertensives than in normotensives (184 +/- 43 versus 146 +/- 23 nmol/l, P less than 0.01). The [Ca2+]i levels in platelets were significantly correlated with both systolic (r = 0.50, P less than 0.05) and diastolic blood pressures (r = 0.57, P less than 0.01). Resting vascular resistance and minimal vascular resistance were significantly higher in essential hypertensives than in normotensives (30.6 +/- 12.6 and 2.57 +/- 1.30 versus 16.3 +/- 8.0 and 1.47 +/- 0.63 mmHg/ml per min per 100 ml, P less than 0.05 and P less than 0.01, respectively). Both resting and minimal vascular resistance were significantly correlated with [Ca2+]i in platelets (r = 0.40 and P less than 0.05, r = 0.55 and P less than 0.01, respectively). These results suggest that [Ca2+]i in platelets reflects [Ca2+]i in vascular smooth muscle cells and may be a significant determinant of not only tone but also structural changes of resistance vessels.
Ueno
H
H
Second Department of Internal Medicine, Toyama Medical and Pharmaceutical University, Japan.
Mikawa
M
M
Takata
M
M
Asanoi
H
H
Iida
H
H
Sasayama
S
S
Kagamimori
S
S
D000328:Adult; D000368:Aged; D001792:Blood Platelets / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008875:Middle Aged; D014655:Vascular Resistance
D002118:Calcium