Studies of a progestogen (MGA)1as related to residues and human consumption
| Autor: | J W Lauderdale, R G Zimbelman, L F Krzeminski, L S Goyings |
|---|---|
| Rok vydání: | 1977 |
| Předmět: |
Estrous cycle
medicine.medical_specialty Mammary tumor Progestogen medicine.medical_treatment media_common.quotation_subject Biology Toxicology Pollution Melengestrol acetate chemistry.chemical_compound Endocrinology chemistry Internal medicine Feedlot medicine Ovulation Carcinogen Hormone media_common |
| Zdroj: | Journal of Toxicology and Environmental Health. 3:5-33 |
| ISSN: | 0098-4108 |
| DOI: | 10.1080/15287397709529546 |
| Popis: | Melengestrol acetate (MGA) is an orally active progestogen that is marketed for improved feed utilization, growth stimulation, and estrus suppression of feedlot heifers. The hormonal activity of MGA was investigated in humans, rhesus monkeys, cattle, dogs, rabbits, mice, and rats. The biologic activities were dose‐dependent within each species and were predictable—that is, block of ovulation and the menstrual or estrous cycle. Subtle effects were not detected for doses below the dose that blocked ovulation. The C3H An/f mouse was investigated for carcinogenic action of MGA. Data derived from the life‐span mouse studies were interpreted as indicating that MGA was not a carcinogen per se, even though massive doses (0.5 mg per mouse daily) could influence mammary tumor development in some instances; this effect was interpreted as being an influence of MGA on the general hormonal milieu. MGA was capable of increasing the serum prolactin concentration of mice fed MGA at a daily rate of about 0.2–0.8 mg. Tissue... |
| Databáze: | OpenAIRE |
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