- 作者: Joen-Rong Sheu, George Hsiaob, Wen-Yi Lin, Tzeng-Fu Chen, Yi-Yi Chien, Chien-Huang Lin, Chiu-Ruey Tzeng
- 作者服務機構: Graduate Institute of Medical Sciences, Departments of Pharmacology and Obstetrics and Gynecology, Taipei Medical University, Taipei, Taiwan, ROC
- 中文摘要: --
- 英文摘要: There is substantial evidence of increased platelet reac-tivity in vivo and in vitro during pregnancy. Platelet acti-vation occurs in pregnancy with a risk of the develop-ment of preeclampsia. In this study, platelet behaviorwas studied during 28-40 weeks of gestation in a groupof women who remained normotensive and a group ofnonpregnant female controls. Platelet aggregation andATP release stimulated by agonists (i.e. collagen andadenosine 5'-diphosphate) were markedly enhanced inwashed platelets from pregnant subjects. Furthermore,the collagen-evoked increase in intracellular Ca ([Ca ] )mobilization in fura-2-AM-loaded platelets was also en-hanced in pregnant subjects. Moreover, the binding ac-tivity of fluorescein isothiocyanate-triflavin toward theplatelet glycoprotein llb/Illa complex did not significantlydiffer between the nonpregnant and pregnant groups. Inaddition, the amount of thromboxane A (TxA ) forma-tion from pregnant subjects was significantly greaterthan that from nonpregnant subjects in both resting andcollagen-activated platelets. On the other hand, prosta-glandin E2 formation in the presence of imidazole in ei-ther resting or arachidonic acid (100 M-treated plate-lets did not significantly differ between these twogroups. The levels of cyclic AMP formation in both rest-ing and prostaglandin E (10 M)-treated platelets frompregnant subjects were significantly lower than those innonpregnant subjects. Nitric oxide production was mea-sured by a chemiluminescence detection method in thisstudy. The extent of nitrate production in either resting orcollagen-stimulated platelets from pregnant subjects didnot significantly differ from that of platelets from thenonpregnant group. We conclude that the agonist-induced hyperaggregability of platelets from normalpregnancy may be due, at least partly, to an increase inTxA formation and a lowering of the level of cyclic AMPformation, which leads to increased [Ca ] mobilizationand finally to enhanced platelet aggregation and ATPrelease.
- 中文關鍵字: --
- 英文關鍵字: Platelets, Hyperaggregability, Thromboxane A2, Cyclic AMP, Normal pregnancy