Non-breeding gonadal testosterone production of male and female Northern Cardinals (Cardinalis cardinalis) following GnRH challenge

作者：DeVries M Susan^*; Holbrook Aaron L; Winters Caitlin P; Jawor Jodie M

来源：General and Comparative Endocrinology, 2011, 174(3): 370-378.

DOI：10.1016/j.ygcen.2011.09.016

• Gonadotropin-releasing hormone
• Testosterone
• Non-breeding
• Birds
• Cardinals

Yearly, testosterone (T) levels fluctuate as many vertebrates cycle through reproductive and non-reproductive periods. Among many temperate birds, it is well established that levels of T peak as gonads recrudesce for breeding and then fall as gonads regress prior to the non-breeding season. While the tissues producing breeding season T are well studied, the tissues responsible for non-breeding T have received less investigative attention. We examined the ability of male and female Northern Cardinals (Cardinalis cardinalis) to elevate gonadal T following standardized injections of gonadotropin-releasing hormone (GnRH) across three non-breeding seasons. Males and females were capable of significantly elevating gonadal T production following GnRH injections during periods of reproductive quiescence. The magnitude of T elevation varied across the non-breeding season, but not between sexes. To our knowledge, this is the first report of a significant increase in gonadal T production following GnRH injections administered in the non-breeding season.

• 出版日期2011-12-1