Lance V A, Grumbles J S, Rostal D C
Center for Reproduction of Endangered Species, San Diego, California 92112, USA.
J Exp Zool. 2001 Apr 15;289(5):285-9.
Blood samples from 30 female and 20 male adult desert tortoises, Gopherus agassizii, were collected at monthly intervals during the annual reproductive cycle (April to October). Plasma corticosterone and the sex steroids in each of the samples were analyzed by radioimmunoassay. Mean corticosterone levels in males were significantly higher than in females (P < 0.001) in every month. Male tortoises showed a marked seasonal pattern in plasma corticosterone with a highly significant peak in July, August, September, and October that corresponded with a similar peak in plasma testosterone. Testosterone and corticosterone in the male showed a highly significant correlation (P < 0.0001). The pattern of corticosterone in the female was less marked, with a significant peak in May during the mating and nesting season, but no association with the peak in estradiol in late summer was apparent. The highest levels of corticosterone in the males were associated with the peak in spermatogenesis and intense male-male combat. These results support similar data from other reptiles that suggest increased glucocorticoid secretion during periods of increased activity and metabolism.
在年度繁殖周期（4月至10月）期间，每月采集30只成年雌性和20只成年雄性沙漠陆龟（阿加西氏陆龟）的血样。通过放射免疫分析法分析每个样本中的血浆皮质酮和性类固醇。每个月雄性的平均皮质酮水平均显著高于雌性（P < 0.001）。雄性陆龟血浆皮质酮呈现明显的季节性模式，在7月、8月、9月和10月出现高度显著的峰值，这与血浆睾酮的类似峰值相对应。雄性体内的睾酮和皮质酮呈现高度显著的相关性（P < 0.0001）。雌性皮质酮的模式不太明显，在交配和筑巢季节的5月出现显著峰值，但与夏末雌二醇的峰值没有明显关联。雄性体内皮质酮的最高水平与精子发生的峰值和激烈的雄性间争斗有关。这些结果支持了来自其他爬行动物的类似数据，表明在活动和代谢增加的时期糖皮质激素分泌增加。
