The cytoplasmic concentration of free calcium in platelets is controlled by stimulators of cyclic AMP production (PGD 2, PGE 1, forskolin)

• Published in: Biochemical and biophysical research communications Vol. 113; no. 2; pp. 598 - 604
• Main Authors: Feinstein, M.B., Egan, J.J., Sha'afi, R.I., White, J.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.06.1983
• Subjects: Alprostadil; Blood Platelets - drug effects; Blood Platelets - metabolism; Calcium - blood; Chemical Phenomena; Chemistry; Colforsin; Cyclic AMP - biosynthesis; Cytoplasm - metabolism; Diterpenes - pharmacology; Humans; In Vitro Techniques; Prostaglandin D2; Prostaglandins - pharmacology; Prostaglandins D - pharmacology; Prostaglandins E - pharmacology; Spectrometry, Fluorescence
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/0006-291X(83)91768-0

Maximal stimulation of platelets with thrombin results in a rapid increase in cytoplasmic Ca 2+ (from 0.1 μM to 1–3 μM), as measured with the fluorescent intracellular Ca 2+ indicator Quin-2. Prior addition of the adenylate cyclase stimulators PGD 2, PGE 1 or forskolin inhibited the rise in cytoplasmic Ca 2+. When added after the maximal response to thrombin was attained adenylate cyclase stimulators caused a rapid fall of cytoplasmic Ca 2+ back to the original “resting” level. This effect coincides with the reversal of thrombin-induced, Ca 2+-dependent protein phosphorylation, and cytoskeleton assembly. It is suggested that cAMP-dependent reactions maintain low levels of cytoplasmic Ca 2+ by promoting transport and/or binding of Ca 2+.