Content and thrombin-induced release of acid hydrolases in gel-filtered
platelets from patients with storage pool disease
H Holmsen, CA Setkowsky, B Lages, HJ Day, HJ Weiss and MC Scrutton
The levels of four acid hydrolases, beta-N-acetyl glucosaminidase, beta-
glucuronidase, beta-galactosidase, and acid phosphatase, and the extent of
their release (release II) by thrombin was determined in platelets from
nine normal subjects, nine patients with storage pool disease, and in
normal platelets which had been exposed to aspirin. The levels of all four
hydrolases were normal in patients with SPD. However, release of three of
these hydrolases (acid phosphatase was an exception) by low concentrations
of thrombin (0.015 and 0.04 U/ml) was decreased in the patients as a group,
although considerable variation in the extent of release of each enzyme was
noted. In contrast, aspirin failed to inhibit release II in normal
platelets (except for a slight impairment in the release of beta-N-acetyl
glucosaminidase), although release I (serotonin, ATP and ADP) was
inhibited. All release defects could be overcome by using higher
concentrations of thrombin (0.2 U/ml). The normal levels of acid hydrolases
in the platelets of patients with SPD (who are deficient in the platelet
dense granules) suggest that these enzymes are not normally stored in the
dense granules, but rather in alpha-granules. The findings also support the
conclusions of previous studies that the release reaction is impaired in
SPD. This release defect appears to be different from that seen in normal
platelets after exposure to aspirin.
Volume 46,
Issue 1,
pp. 131-142,
07/01/1975
Copyright © 1975 by The American Society of Hematology
