In this task, you are given a sentence. You are expected to recognize the name of any form of chemical substances. Although there might be several correct answers, you need to write one of them.

Q: Binding and GTPgammaS autoradiographic analysis of preproorphanin precursor peptide products at the ORL1 and opioid receptors.

A: GTPgammaS
****
Q: Distinct role of PYK2 in mediating thromboxane generation downstream of both G12/13 and integrin αiibβ in platelets.

A: thromboxane
****
Q: Nicotine-induced contraction in the rat coronary artery: possible involvement of the endothelium, reactive oxygen species and COX-1 metabolites.

A:
oxygen
****
