title: The effect of a synthetic steroid (trienbolone) on the rate of release and excretion of subcutaneously administered estradiol in calves (18).
abstract: With the objective of obtaining values for the rate of release and excretion of subcutaneously implanted estradiol and to relate them to the metabolic effect of the hormone, a study was carried out with young Jersey bull calves. After subcutaneous administration of lactose tablets (implants) containing tritiated estradiol (4 mCi in 20 mg estradiol) the activity was followed in plasma, urine and feces for 107 days. Three calves received implants containing 140 mg trienbolone in addition to the 20 mg estradiol. In the first group maximum plasma concentration of estradiol-17 beta was 3 nmol/1. In the other group it was only 0.33 nmol/1. In calves receiving estradiol as the only steroid, 95% of the activity was excreted within 20 days after implantation. In the other group collection of urine and feces had to be carried out for 107 days in order to account for all the implanted activity. No 3H could be detected in urine and feces samples collected from the estradiol group more than 31 days ater implantation. The feces and urine samples collected from calves in the estradiol-trienbolone group 107 days after implantation contained from 1.4 - 3 nCi per gram. The remarkably decreasing effect of trienbolone on the release of estradiol and its possible importance for the effect of subcutaneously administered estradiol are discussed.
mesh_terms: D045930:Anabolic Agents / Q000494:pharmacology*; D000818:Animals; D002417:Cattle; D004343:Drug Implants; D004958:Estradiol / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*; D004963:Estrenes / Q000494:pharmacology*; D005243:Feces / Q000032:analysis; D007279:Injections, Subcutaneous; D008297:Male; D013997:Time Factors
chemical_list: D045930:Anabolic Agents; D004343:Drug Implants; D004963:Estrenes; D004958:Estradiol