Mechanism of the cytoprotective effect of prostaglandin I2 and its analogue in human platelets.
The responsiveness of washed human platelets to thrombin was well preserved up to 72 and 96 hours, when they were stored at 4 degrees C with prostaglandin I2 (PGI2) and its stable analogue OP-41483, respectively, while the washed platelets stored with sodium citrate completely lost their responsiveness to thrombin at 48 hours. The effect of PGI2 or the analogue on the resting level of intraplatelet Ca2+ concentration ([Ca2+]i) was investigated, utilizing fluorescent Ca2+ indicator quin 2. PGI2 lowered the resting [Ca2+]i in a dose related manner in the presence or absence of the extracellular Ca2+. The similar results were obtained when OP-41483 was added to the quin 2 loaded platelets. From these results, it was concluded that the lowering of the resting [Ca2+]i may be the prerequisite for the cytoprotective effect of PGI2 or OP-41483.
D000634:Aminoquinolines; D001792:Blood Platelets / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D001793:Blood Preservation; D002118:Calcium / Q000097:blood; D011464:Epoprostenol / Q000494:pharmacology* / Q000031:analogs & derivatives; D005615:Freezing; D006801:Humans; D013917:Thrombin / Q000502:physiology
D000634:Aminoquinolines; D011464:Epoprostenol; D013917:Thrombin; C035847:ataprost; C035739:Quin2; D002118:Calcium