STEREOLOGIC EVALUATION ON INVITRO THROMBIN-INDUCED PLATELET DEGRANULATION AND CONTRACTION

  • 1 January 1978
    • journal article
    • research article
    • Vol. 20  (2) , 173-178
Abstract
Stereologic study of the in vitro release reaction from unstirred washed platelets provided quantitative information on the contractile wave induced by thrombin. Contraction was estimated from the reduction in the volume of the granular compartment and the vacuoles of the surface connected canalicular system. Dibutyryl cyclic-AMP (10-4 M) and dipyridamole (10-3 M) inhibited degranulation, but they had no effect on the contraction produced by thrombin at high concentrations (0.1 IU/ml). Aspirin (10-4 M) inhibited contraction induced by thrombin at concentration of 0.1 and 0.02 IU/ml (P < 0.01 at each concentration). In 2 patients with hereditary cyclooxygenase deficiency, contraction normally produced by thrombin at low concentration (0.02 IU/ml) failed to induce contraction.