Fig. 6.
Temperature dependence of the [Ca2+]i signal induced by exogenous arachidonic acid. The [Ca2+]i transient in a stirred suspension of human platelets (50,000 cells/μL) was monitored with Fura-PE3. The platelets were stimulated at 20°C (A), 30°C (B), or 37°C (C) by 20 μmol/L arachidonic acid (solid traces) in the presence of extracellular calcium (1 mmol/L CaCl2). Data obtained in parallel control studies with 0.2% (wt/vol) dimethylsulfoxide (vehicle for arachidonic acid; dotted traces) are also displayed. Observations at 25°C (not shown) were indistinguishable from those at 20°C. The results illustrated are from a typical one of seven such studies.