Changes in phosphatidylinositol-4,5-bisphosphate 10 seconds after stimulation of washed rabbit platelets with ADP.
نویسندگان
چکیده
Adenosine diphosphate (ADP) induced aggregation of rabbit platelets, without the release reaction, causes a significant decrease (7%) in the amount of phosphatidylinositol-4,5-bisphosphate (PIP2) at 10 sec and at 60 sec (11%). In platelets prelabeled with 32P-phosphate, this decrease in PIP2 is associated with a decrease in PIP2 radioactivity, which is significant at 50 sec. The decrease in PIP2 is sufficient to mobilize about 0.18 nmole Ca2+/10(9) platelets. In view of the key role played by Ca2+ in ADP-induced platelet shape change and aggregation, this evidence is compatible with the hypothesis that changes in PIP2 can be a source of calcium for cellular responses to agonists.
منابع مشابه
Involvement of phosphoinositide metabolism in potentiation by adrenaline of ADP-induced aggregation of rabbit platelets.
Changes in phosphoinositide metabolism were examined in washed rabbit platelets stimulated with 0.5 microM-ADP, 50 microM-adrenaline, or ADP and adrenaline in combination. Adrenaline does not stimulate platelet aggregation when used alone, but does potentiate aggregation stimulated by ADP. In platelets prelabelled with [32P]Pi and [3H]glycerol, adrenaline was found to potentiate the ADP-induced...
متن کاملBreakdown of polyphosphoinositides and not phosphatidylinositol accounts for muscarinic agonist-stimulated inositol phospholipid metabolism in rat parotid glands.
The molecular mechanisms underlying the ability of muscarinic agonists to enhance the metabolism of inositol phospholipids were studied using rat parotid gland slices prelabelled with tracer quantities of [3H]inositol and then washed with 10 mM unlabelled inositol. Carbachol treatment caused rapid and marked increases in the levels of radioactive inositol 1-phosphate, inositol 1,4-bisphosphate,...
متن کاملInositol lipids, phosphatidate and diacylglycerol share stearoylarachidonoylglycerol as a common backbone in thrombin-stimulated human platelets.
Gel-filtered human platelets were stimulated with 5i.u. of thrombin/ml for times up to 1 min. The fatty acid composition of inositol-containing phospholipids, phosphatidic acid and diacylglycerol was determined by g.l.c. in control and thrombin-stimulated platelet suspensions. Inositol phospholipids were found to have similar proportions of stearic and arachidonic acids, the sum of these repres...
متن کاملPhosphatidylinositol 4,5-bisphosphate is selectively retained by platelet-fibrin clots formed by thrombin.
Stimulation of human or rabbit platelets with thrombin in the presence of fibrinogen caused a large decrease, compared with unstimulated controls, in the amount of phosphatidylinositol 4,5-bisphosphate (PIP2) that could be extracted with acidified chloroform/methanol (60% at 60 s). In contrast, stimulation in the absence of added fibrinogen increased the amount of PIP2. The decrease was specifi...
متن کاملThrombin-induced inositol trisphosphate production by rabbit
Ethanol has an inhibitory effect on some platelet functions, but the mechanisms by which it exerts this effect are not known. Using suspensions of washed platelets, we observed that ethanol (1-9 mg/ml) did not affect the aggregation of rabbit platelets stimulated with ADP (O.5-10 /M). When platelets were prelabelled with 5-hydroxy[14C]tryptamine, aggregation and secretion of granule contents in...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Blood
دوره 60 6 شماره
صفحات -
تاریخ انتشار 1982