Collagen-mediated platelet aggregation and secretion of dense granule ATP is diminished in ashen mutants on the C3H/HeSnJ background but unaffected in ashen mutants on the a/a, ash/ashbackground.

Platelet aggregation was determined by the impedance method in whole blood in response to 4 μg/mL (A,C) and 1 μg/mL (B,D) collagen. A, B: C3H/HeSnJ ash/ash; C, D: a/a, ash/ash. In all cases, “normal” refers to the C3H/HeSnJ strain. ATP release was determined by luminescence methods. The small arrows indicate the time of addition of collagen.