کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5510321 | 1538983 | 2017 | 8 صفحه PDF | دانلود رایگان |
The modulation exerted by glucocorticoids in physiological responses to stressors is essential for maintaining short-term homeostasis. However, highly frequent and/or prolonged activation of the hypothalamic-pituitary-adrenal/interrenal axis may inhibit processes that are important to long-term fitness and health, including reproduction and immunocompetence. The present study evaluates the response to adrenocorticotropic hormone (ACTH) injection in the adult male tree frog, Hypsiboas faber, as indicated by levels of plasma corticosterone (CORT), plasma testosterone (T), ocular melatonin (MEL), hematocrit and immune functioning (total leukocyte count and bacterial killing ability against Escherichia coli). All levels were measured 1, 3 and 6Â h after treatment. ACTH increased CORT levels whilst decreasing T and MEL levels at 1Â h post-treatment. 6Â h after ACTH injection, hematocrit and MEL levels increased. ACTH treatment did not significantly modulate the immune measures over the time-range sampled. The hormonal changes observed in response to ACTH treatment suggest that stressors could act as inhibitors of reproductive activity, as well as differentially modulating melatonin levels at different time-points.
Journal: Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology - Volume 204, February 2017, Pages 177-184