Intracellular Ca2+ stimulates the binding to androgen receptors in platelets.

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Cabeza M, Flores M, Bratoeff E, de la Pena A, Mendez E, Ceballos G

Intracellular Ca2+ stimulates the binding to androgen receptors in platelets.

Steroids. 2004 Oct-Nov;69(11-12):767-72.

PubMed ID

15579329 [ View in PubMed

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Abstract

In this study, we demonstrated that ADP-induced platelet aggregation activates the binding of testosterone (T) to its receptor. It is well known that binding of ADP to its receptors induced the release of Ca2+ ions from dense bodies into the cytosol of platelets. In this work, we compared the binding of testosterone or dihydrotestosterone to their receptors using cytosol obtained from ADP-treated and non-treated platelets. These experiments were repeated using EGTA (a calcium chelator) or U73122 (a phospholipase C enzymatic activity inhibitor) to the ADP-treated platelets. In addition, we also developed a competition analysis for the androgen receptors (AR) using [3H]DHT, non-radioactive T, DHT or cyproterone acetate from ADP-treated platelets cytosol. The results from this study indicate that the cytosol obtained from non-ADP-treated platelets did not show any binding to [3H]T or [3H]DHT, whereas cytosol from ADP-treated platelets binds to the radio-labeled androgens. Furthermore cytosol from ADP plus U73122-treated platelets did not show binding to [3H]T or [3H]DHT. These data suggest that intracellular Ca2+ ions stimulates the binding of androgens to their receptors in platelets cytosol. The competition analysis shows that T and DHT have high affinities for the androgen receptors with similar IC50 values, whereas cyproterone acetate shows a lower affinity. The results from these data clearly indicate the presence of androgen receptors in platelets.

DrugBank Data that Cites this Article

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
Cyproterone acetate	Androgen receptor	Protein	Humans	Yes	Antagonist	Details