[PI metabolism and Ca mobilization in patients with platelet dysfunction].
The effect of STA2, thrombin and NaF on PI metabolism and Ca mobilization was investigated in patients with three kinds of platelet dysfunction, one each with platelet cyclo-oxygenase deficiency (A), defective aggregation to A23187 (B) and defective aggregation to STA2 (C). These responses were normal in patient (A), suggesting cyclooxygenase activity did not affect PI metabolism and Ca mobilization. PI metabolism was also normal in (B), although Ca mobilization in response to A23187 was delayed and that in response to thrombin was defective in the presence of extracellular Ca2+. This suggests that the patient's platelets have a defective IP3-induced Ca mobilization pathway. STA2 selectively failed to induce IP3 formation and Ca mobilization in (C), although 3H-labelled thromboxane ligand (3H-U46619) bound to the patient's platelets normally. It was suggested that the patient's platelets have a defect in postreceptor signal transduction, especially thromboxane receptor-mediated PLC activation pathway.
Fuse
I
I
First Department of Internal Medicine, Niigata University School of Medicine.
Hattori
A
A
Higuchi
W
W
Shibata
A
A
D001778:Blood Coagulation Disorders / Q000378:metabolism* / Q000503:physiopathology; D001792:Blood Platelets / Q000378:metabolism; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D006801:Humans; D010716:Phosphatidylinositols / Q000378:metabolism*; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D011451:Prostaglandin-Endoperoxide Synthases / Q000172:deficiency; D011982:Receptors, Prostaglandin / Q000378:metabolism; D017482:Receptors, Thromboxane; D015398:Signal Transduction; D012969:Sodium Fluoride / Q000494:pharmacology; D013917:Thrombin / Q000494:pharmacology; D013928:Thromboxane A2 / Q000494:pharmacology; D010738:Type C Phospholipases / Q000378:metabolism
D010716:Phosphatidylinositols; D010975:Platelet Aggregation Inhibitors; D011982:Receptors, Prostaglandin; D017482:Receptors, Thromboxane; D000001:Calcimycin; D013928:Thromboxane A2; D012969:Sodium Fluoride; D011451:Prostaglandin-Endoperoxide Synthases; D010738:Type C Phospholipases; D013917:Thrombin; D002118:Calcium