Growth hormone, insulin, prolactin and total thyroxine in the plasma of sheep implanted with the anabolic steroid trenbolone acetate alone or with oestradiol.
The mode of action of the anabolic steroid trenbolone acetate (19-norandrost-4,9,11-trien-3-one-17-acetate) was studied through the endogenous hormonal response of castrated male sheep to subcutaneous implantation of 140 mg of trenbolone acetate and 20 mg of oestradiol both separately and in combination. Radioimmunoassay of delta-4,9,11-trienic steroids and oestradiol-17 beta in plasma confirmed that simultaneous administration of trenbolone acetate with oestradiol led to a significantly greater persistence of oestradiol-17 beta residues in plasma (P less than 0.05) than with implantation of oestradiol alone. Oestradiol treatment increased concentrations of growth hormone and insulin (P less than 0.05; P less than 0.001 respectively) in plasma samples collected weekly. Trenbolone acetate by itself had no significant effect and the oestrogenic response was blocked on the simultaneous implantation of trenbolone acetate and oestradiol (despite higher plasma levels of oestradiol-17 beta with this treatment). Plasma total thyroxine was markedly depressed to 45 per cent of its basal level by trenbolone acetate, alone or with oestradiol (P less than 0.001) and depressed to 80 per cent of basal by oestradiol treatment alone (P less than 0.001). Plasma prolactin was unaltered by the above treatments.
D000818:Animals; D001835:Body Weight; D004958:Estradiol / Q000494:pharmacology*; D004963:Estrenes / Q000494:pharmacology*; D013006:Growth Hormone / Q000097:blood; D007328:Insulin / Q000097:blood; D008297:Male; D011388:Prolactin / Q000097:blood; D012756:Sheep / Q000097:blood* / Q000254:growth & development / Q000502:physiology; D013974:Thyroxine / Q000097:blood; D014204:Trenbolone Acetate / Q000494:pharmacology*
D004963:Estrenes; D007328:Insulin; D004958:Estradiol; D011388:Prolactin; D013006:Growth Hormone; D013974:Thyroxine; D014204:Trenbolone Acetate