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.

[EX Q]: Increased responsiveness of rat colonic splanchnic afferents to 5-HT after inflammation and recovery.
[EX A]: 5-HT

[EX Q]: Use of the norepinephrine transporter as a reporter gene for non-invasive imaging of genetically modified cells.
[EX A]: norepinephrine

[EX Q]: Development of hypoxia-inducible factor (HIF)-1α inhibitors: effect of ortho-carborane substituents on HIF transcriptional activity under hypoxia.
[EX A]:
ortho-carborane