Open AccessPlatelet calcium homeostasis is abnormal in patients with severe arteriosclerosis.
Author(s) -
A. Vicari,
M. Monzani,
Fabio Pellegatta,
Paola Ronchi,
Laura Galli,
Franco Folli
Publication year - 1994
Publication title -
arteriosclerosis and thrombosis
Language(s) - English
Resource type - Journals
eISSN - 2330-9199
pISSN - 1049-8834
DOI - 10.1161/01.atv.14.9.1420
Subject(s) - platelet , calcium metabolism , homeostasis , calcium , medicine , endocrinology , thrombin , arteriosclerosis , chemistry , fura 2 , platelet activation , extracellular , biochemistry , enzyme , cytosol
To evaluate platelet calcium homeostasis in a typical thrombosis-prone clinical condition, 14 patients with severe arteriosclerosis and 11 healthy control subjects were studied. Platelet intracellular free calcium concentration ([Ca2+]i) was evaluated by means of the fluorescent probe fura 2 under resting conditions and after challenge with 0.05, 0.1, and 0.5 U/mL thrombin (final concentrations). Three different concentrations of extracellular ionized calcium ([Ca2+]e) were used: 1 mmol/L, 1 mumol/L, and < 1 nmol/L. Resting platelet [Ca2+]i was significantly higher (P < .001) in patients than in control subjects. After addition of 0.05 U/mL thrombin, the relative increase of [Ca2+]i was lower in patients than in control subjects in each of the three [Ca2+]e conditions (P = .05 at 1 mmol/L, P = .02 at 1 mumol/L, and P = .04 at < 1 nmol/L). After addition of 0.1 U/mL thrombin, the relative increase of [Ca2+]i was lower in patients than in control subjects under two [Ca2+]e conditions, 1 mumol/L and < 1 nmol/L (P = .04 and P = .03 respectively). With 0.5 U/mL thrombin, a trend toward lower values in patients than in control subjects was observed, reaching statistical significance (P = .03) only at < 1 nmol/L [Ca2+]e. These results suggest that calcium homeostasis is abnormal in platelets from patients with severe arteriosclerosis and probably reflects a chronic activation.