Free Ca2+ requirements of agonist-induced thromboxane A2 synthesis in human platelets.
In quin2-loaded human platelets ionomycin raised cytosolic free calcium to greater than 1 microM and generated less than 1 ng thromboxane. Collagen alone or in the presence of EPO92 generated up to 32 and 16 ng thromboxane respectively; in the latter case at calcium levels around 120 nM. Thrombin maximally raised calcium to greater than 1 microM and generated up to 27 ng thromboxane, although in the presence of 1 mM EGTA these calcium and thromboxane levels were reduced to 200 nM and 5 ng respectively.
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001792:Blood Platelets / Q000378:metabolism*; D002118:Calcium / Q000502:physiology*; D003094:Collagen / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D004987:Ethers / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D015759:Ionomycin; D013917:Thrombin / Q000494:pharmacology; D013928:Thromboxane A2 / Q000096:biosynthesis*
D000900:Anti-Bacterial Agents; D004987:Ethers; D004533:Egtazic Acid; D015759:Ionomycin; D013928:Thromboxane A2; D003094:Collagen; D013917:Thrombin; D002118:Calcium