کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2799775 1568872 2016 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Sources of variation in plasma corticosterone and dehydroepiandrosterone in the male northern cardinal (Cardinalis cardinalis): I. Seasonal patterns and effects of stress and adrenocorticotropic hormone
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی علوم غدد
پیش نمایش صفحه اول مقاله
Sources of variation in plasma corticosterone and dehydroepiandrosterone in the male northern cardinal (Cardinalis cardinalis): I. Seasonal patterns and effects of stress and adrenocorticotropic hormone
چکیده انگلیسی


• Restraint stress increases corticosterone (CORT), but decreases dehydroepiandrosterone (DHEA) levels in cardinals.
• Decreased DHEA levels with restraint stress only observed in jugular circulation.
• ACTH does not increase DHEA levels, but increases CORT.
• Both CORT and DHEA were generally lowest in the fall and highest during spring.

The secretion of steroids from the adrenal gland is a classic endocrine response to perturbations that can affect homeostasis. During an acute stress response, glucocorticoids (GC), such as corticosterone (CORT), prepare the metabolic physiology and cognitive abilities of an animal in a manner that promotes survival during changing conditions. Although GC functions during stress are well established, much less is understood concerning how adrenal androgens, namely dehydroepiandrosterone (DHEA) are influenced by stress. I conducted three field studies (one experimental and two descriptive) aimed at identifying how both CORT and DHEA secretion in free-living male northern cardinals (Cardinalis cardinalis), vary during acute stress; across different circulations (brachial vs. jugular); in response to ACTH challenge; and during the annual cycle. As predicted, restraint stress increased plasma CORT, but unexpectedly DHEA levels decreased, but the latter effect was only seen for blood sampled from the jugular vein, and not the brachial. The difference in DHEA between circulations may result from increased neural uptake of DHEA during stress. Injection with exogenous adrenocorticotropic hormone (ACTH) increased CORT concentrations, but failed to alter DHEA levels, thus suggesting ACTH is not a direct regulator of DHEA. Monthly field sampling revealed distinct seasonal patterns to both initial and restraint stress CORT and DHEA levels with distinct differences in the steroid milieu between breeding and non-breeding seasons. These data suggest that the CORT response to stress remains relatively consistent, but DHEA secretion is largely independent of the response by CORT. Although CORT functions have been well-studied in wild animals, little research exists for the role of DHEA and their variable relationship sets the stage for future experimental research addressing steroid stress responses.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: General and Comparative Endocrinology - Volume 235, 1 September 2016, Pages 192–200
نویسندگان
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