Elevation of cytosolic free Ca2+ is directly evoked by thromboxane A2 in human platelets during activation with collagen

J Biochem. 1988 Jun;103(6):901-2. doi: 10.1093/oxfordjournals.jbchem.a122383.

Abstract

The thromboxane A2 antagonist, ONO-3708, completely inhibited the increase in cytosolic free Ca2+ in human platelets during activation with collagen. Half-maximal Ca2+ release and influx required about 3 and 4 nM STA2, a stable thromboxane A2 mimetic, respectively. However, half maximal activation of phospholipase C required about 18 nM STA2. This suggests that thromboxane A2 directly causes Ca2+ mobilization without further activation of phospholipase C during activation of human platelets with collagen.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blood Platelets / metabolism*
  • Calcium / metabolism*
  • Collagen / pharmacology*
  • Cytosol / metabolism*
  • Enzyme Activation
  • Humans
  • In Vitro Techniques
  • Platelet Activating Factor / pharmacology*
  • Thromboxane A2 / analogs & derivatives
  • Thromboxane A2 / antagonists & inhibitors
  • Thromboxane A2 / pharmacology
  • Thromboxane A2 / physiology*
  • Type C Phospholipases / metabolism

Substances

  • Platelet Activating Factor
  • Thromboxane A2
  • ONO 3708
  • Collagen
  • Type C Phospholipases
  • Calcium