An Assessment of Androgenic/Anti­androgenic Effects of GH Transgenic Carp by Hershberger Assay*

Abstract Objective To evaluate the androgenic and anti-androgenic effects of GH (growth hormone) transgenic carp in male rats. Methods Hershberger assay was carried out in castrated male SD rats aged 4-5 weeks. Testosterone propionate (TP) (0.4 mg/kg BW) was administrated for a positive control, GH transgenic carp (3.0 g/kg BW)+TP (0.4 mg/kg BW), parental carp (3.0 g/kg BW) + TP (0.4 mg/kg BW), and flutamide (Flu) (3.0 g/kg BW) were used for negative controls, and vehicle was administered orally for a blank control. All groups were administrated for 10 consecutive days. At the end of the test, animals were anesthetized, then weights of accessory sex organ were measured. Serum testosterone (T), luteinizing hormone (LH), and Follicle-Stimulating Hormone (FSH) levels were detected. Results The weights ratios of the accessory sex organs and body weights showed no significant differences between the solvent control and the GH transgenic carp-treated groups. Serum concentrations of FSH, LH, and T of the rats treated with GH transgenic carp + TP showed no significant changes, compared with those treated with TP only. Conclusion GH transgenic carp does not have any androgenic agonist or antagonist properties in vivo screening tests.