Table 4.

Changes of expression of zebrafish proenkephalins and proopiomelanocortin in morphine-treated embryos.

	dre-penk a	dre-penk b	dre-pomc a
24 hpf	0.61 ± 0.12	1.32 ± 0.05a	0.90 ± 0.01
48 hpf	1.45 ± 0.06b	1.31 ± 0.10a	0.48 ± 0.15b

Results represent the relative gene expression fold-changes of dre-penk a, dre-penk b and dre-pomc a in morphine-treated embryos of 24 and 48 hpf. Data shown are normalized to dr-eef1a1l1. A total of 50 embryos were used for each treatment and for each time point; the experiment was performed in triplicate and repeated four times.

^ap < 0.01 and

^bp < 0.05 (unpaired Student t test, n = 4).