Table 3.

Examples of read-across hypothesis studies based on fish plasma model about human drugs

Drug	Target System	Species	EEC	FPC (μg/L)		MOA-relevant Endpoints	Measured FPC compared to HTPC	Reference
				Predicted FPC	Measured FPC
Sertraline (log D7.4 = 3.77)	Central nervous System (antidepressant)	Fathead minnow (Pimephalespromelas)	3, 10, 30 μg/L	Predicted FPC ≈ Measured FPC		•Plasma drug concentration •SERT binding •Behavior	> HTPC	Valenti et al.22
Fluoxetine (log D7.4 = 1.99)	Central nervous System (antidepressant)	Fathead minnow (Pimephalespromelas)	0.1, 1, 10, 20, 38, 72 mg/L	When EEC >10 mg/L: Predicted FPC < Measured FPC		•Plasma drug concentration •Drug metabolism •Behavior	0.1, 1, 10 mg/L: < HTPC 20 mg/L: ≈ HTPC 38, 72 mg/L: > HTPC	Margiotta et al.21
Oxazepam (log D7.4 = 2.63)	Central nervous System (Anti-anxiety)	Fathead minnow (Pimephalespromelas)	0.8, 4.7, 30.6 μg/L	Female: Predicted FPC > Measured FPC		•Drug concentration in plasma, brain, liver, muscle •Behavior	30.6 μg/L: ≤ HTPC	Huerta et al.18
Tramadol (log Kow, log Dow, log Dlipw)	Central nervous System (analgesic)	Fathead minnow (Pimephalespromelas)	1, 10, 100 μg/L	Predicted FPC > Measured FPC		•Drug concentration in plasma and brain •Drug metabolism •Behavior	< HTPC	Tanoue et al.19
25 compounds	Central nervous system	Zebrafish (Danio rerio)	0.625, 1.25, 2.5, 0, 0.3125, 5 mM	–	–	•Seizure-like behavior •Maximum tolerated concentration	–	Winter et al.70
57 compounds	Central nervous system	Zebrafish (Danio rerio)	1.25, 2.5, 5 mM	–	–	•Whole-body drug concentration •Behavior •Brain activity	–	Winter et al.71
100 compounds	Cardiovascular system	Zebrafish (Danio rerio)	10, 100, 1000 μg/mL	–	–	•Heart rate	–	Milan et al.72
Adrenaline Cisapride Haloperidol Terfenadine Theophylline Verapamil	Cardiovascular system	Zebrafish (Danio rerio)	10, 20,40; 0.05, 0.075, 0.10; 0.0025, 0.05, 0.010; 0.4, 1.6, 1.8; 0.0001, 0.001, 0.10; 0.25, 0.50, 1; 0.05, 0.075, 010 mmol/L	–	–	•Whole-body drug concentration •Maximum tolerated concentration •Heart rate •Atrium:ventriculum beat ratio •Stroke volume •Blood flow •Blood vessel diameter	–	Parker et al.73
Gesogestrel Drospirenone Gestodene Levonorgestrel	Reproductive system	Fathead minnow (Pimephalespromelas)	100 ng/L; 100 ng/L; 1, 10, 100 ng/L; 0.1, 1, and 10 μg/L	–	–	•Reproductive activity •Egg production •Breeding frequency •SSCs	–	Runnalls et al.74
Dutasteride	Reproductive system	Fathead minnow (Pimephalespromelas)	10, 32, and 100 μg/L	–	–	•Reproductive activity •Egg production •Breeding frequency •SSCs •Plasma E2, T, 11-KT •Gonad histopathology •Sperm quality	–	Margiotta-Casaluci et al.75
Ethinylestradiol Levonorgestrel (log Kow = 3.72; log D7.4 = 3.32)	Reproductive system	Fathead minnow (Pimephalespromelas)	Ethinylestradiol: 0.25, 2.5, 12.5 ng/L(mixture exposure) Levonorgestrel: 0.25, 2.5, 12.5 ng/L(mixture exposure, measured: 5.2 and 15.8 ng/L)	Levonorgestrel (log Kow = 3.72): Predicted FPC ≈ Measured FPC Levonorgestrel (log D7.4 = 3.32): Predicted FPC < Measured FPC		•Plasma drug concentration •Reproductive activity •Egg production •Breeding frequency •Plasma E2 and 11-KT •SSCs	Ethinylestradiol except for 0.25 ng/L(single): Predicted FPC ≤ HTPC(0.04–0.16 μg/L) Levonorgestrel: except for 100 ng/L(single): Predicted FPC < HTPC	Runnalls et al.65
Dexamethasone	Reproductive system Respiratory system Development	Fathead minnow (Pimephalespromelas)	0.1, 1, 10, 100, and 1,000 μg/L	–	–	•Growth •Reproductive activity •Egg production •Breeding frequency •F1 hatching rate •Ex vivo gonad T and E2 production •SSCs •Gill histopathology •Expression of MOA-relevant genes	–	LaLone et al.76
10 synthetic GCs (in vitro) Beclomethasone dipropionate Prednisolone	Immune system Metabolism	Fathead minnow (Pimephalespromelas) Rainbow trout (Oncorhynchusmykiss)	100 ng/L, 1, 10 μg/L	–	–	•Target transactivation •Plasma glucose •Blood leukocyte count	–	Kugathas and Sumpter77
Beclomethasone dipropionate	Immune system Metabolism HPI axis	Fathead minnow (Pimephalespromelas)	0.1, 1, 10 μg/L	–	–	•Plasma cortisol •Plasma glucose •PEPCK and GR gene expression •Blood leukocyte and thrombocyte count •SSCs	–	Kugathas et al.78
Beclomethasone Dipropionate (log Kow = 3.69; log D7.4 = 4.07)	Immune system Metabolism Secondary pharmacology	Fathead minnow (Pimephalespromelas)	10, 100, 1000 ng/L	Predicted FPC ≈ Measured FPC		•Drug metabolism and plasma drug concentration •PEPCK and GR gene expression •Blood glucose •Leukocyte subpopulations response •AR gene expression •SSCs	10 ng/L: within HTPC 1000 ng/L: > HTPC	Margiotta-Casaluci et al.25
Diclofenac	Immune system Renal system GI system	Rainbow trout (Oncorhynchusmykiss)	0.5, 1, 5, 25 μg/L	–	–	•Drug metabolism and bile drug concentration •ptgs1 and ptgs2 gene expression •Kidney, liver, intestine histopathology	–	Mehinto et al.79
Ibuprofen (log Kow = 3.58; log D7.4 = 4.07)	Immune system	Fathead minnow (Pimephalespromelas)	105, 278, 409, 502 μg/L	log Kow = 3.58:105, 278 μg/L: Predicted FPC > Measured FPC; 409, 502 μg/L: Predicted FPC < Measured FPC. log D7.4 = 4.07: Predicted FPC > Measured FPC		•Plasma drug concentration •Prostaglandin E •ptgs1 and ptgs2 gene expression	105 μg/L: < HTPC 78, 409 μg/L: ≈ HTPC 502 μg/L: > HTPC	Patel et al.24

EEC, external exposure concentration; FPC, fish plasma concentration; MOA, mode of action; H_TPC, human therapeutic plasma concentration; SERT, serotonin transporter; SSCs, secondary sexual characteristics; E2, estradiol; T, testosterone; 11-KT, 11 keto-testosterone; GC, glucocorticoid; HPI, hypothalamic–pituitary–interrenal; PEPCK, phosphoenolpyruvate carboxykinase; GR, glucocorticoid receptor; AR, androgen receptor; GI, gastrointestinal; ptgs, prostaglandin-endoperoxide synthase; Predicted FPC ≈ Measured FPC, fish plasma model has a good accuracy; Dow, octanol –water distribution coefficient; Dlipw, liposome-water distribution coefficient.