Effect of Blood Sampling and Administration of ACTH on Cortisol and Progesterone Levels in Ovariectomized Zebu Cows (Bos indicus)
| Autor: | J. M. Bolanos, J. R. Molina, Mats Forsberg |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Costa Rica
Cortisol secretion endocrine system medicine.medical_specialty Hydrocortisone Ovariectomy Acth treatment Article Adrenocorticotropic Hormone Internal medicine Animals Medicine Progesterone Blood Specimen Collection Tropical Climate Venipuncture General Veterinary business.industry General Medicine Single injection Progesterone secretion Zebu Endocrinology Ovariectomized rat Cattle Female business hormones hormone substitutes and hormone antagonists Blood sampling |
| Zdroj: | Acta Vet Scand |
| ISSN: | 1751-0147 |
| Popis: | Four zebu cows were bilaterally ovariectomized through lateral laparotomy. Three months after ovariectomy, blood samples were collected by jugular venipuncture daily for 5 consecutive days prior to a single injection of ACTH to establish baseline concentrations of cortisol and progesterone. Baseline concentrations of cortisol and progesterone were 31 +/- 5 nmol/L and 0.3 +/- 0.01 nmol/L, respectively. On the day of ACTH treatment the cows were allowed to rest for 2 h to reduce the stress of cannulation before the sampling period started. Blood samples were collected every 30 min from 2 h before until 2 h after the injection of 6 micrograms ACTH and hourly between 2-6 h after ACTH injection. A significant increase was observed in cortisol secretion from 90 min before until 120 min after ACTH injection. No significant increase was observed in progesterone secretion before ACTH injection. After ACTH injection progesterone was significantly elevated for 120 min. Four weeks after the ACTH treatment the cows were cannulated again and blood samples were collected following the same bleeding schedule used during the ACTH experiment. Instead of ACTH a saline injection was given via the catheter. A significant increase in cortisol concentration was recorded 90 min before saline injection. This increase was not accompanied by an elevation in progesterone concentration. No significant changes were observed in cortisol and progesterone levels after saline injection. When cortisol was added to a plasma pool having a progesterone concentration of 0.3 nmol/L and a cortisol concentration of 25.4 nmol/L and assayed for progesterone in 2 different assays no increase in progesterone concentration was observed. We conclude that the adrenal glands can be an extra-ovarian source of progesterone during stress in Zebu cows. |
| Databáze: | OpenAIRE |
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