Fig. 4.
Collagen-induced [Ca2+]i and prothrombinase responses of unstirred thrombasthenic platelets. Changes in [Ca2+]i during collagen stimulation without stirring of fura-2–loaded GFP from a control subject and thrombasthenic patients AE, CG, MC, and LW. The response in the control was typical of those obtained in other normal subjects. The correlation between prothrombinase values (indicated in parentheses) obtained in parallel samples and the average [Ca2+]i values (see Materials and Methods) in the patients was significant (r = .978, P < .05).