Fig. 3.
Ca++ influx in response to oleoyl acetyl glycerol (OAG) and thrombin.
Fura-2–loaded platelets were incubated at 37°C in the presence of 1 mM extracellular Ca++ (addition of Ca++marked on traces). Agonists were then added, and the elevations of [Ca++]i were monitored using the 340:380 nm ratio. A calibrated [Ca++]i (nM) scale is shown on the right. Figures given below represent increase in ratio units above basal level after 5 minutes. (A) Cells stimulated with 30, 60, and 90 μM OAG showed linear elevation of [Ca++]i of 0.78 ± 0.156, 0.98 ± 0.162, and 1.08 ± 0.175 ratio units, respectively (n = 11). (B) Cells stimulated with 1 U/mL thrombin showed rapid [Ca++]i increase with a peak value of 2.4 ± 0.787 ratio units (n = 6), followed by a slow decrease to a plateau value after 5 minutes of 1.35 ± 0.57 ratio units (n = 6).