Weiss S L, Moore M C
Department of Biology, Arizona State University, Tempe, AZ 85287-1501, USA.
Gen Comp Endocrinol. 2004 Apr;136(2):282-8. doi: 10.1016/j.ygcen.2004.01.001.
Testosterone is usually thought to be the major sex steroid regulating adult male territorial aggression in vertebrates. However, recent evidence has suggested a role for progesterone, as well as testosterone, in the organization of the two male reproductive phenotypes of tree lizards (Urosaurus ornatus), which differ in adult levels of territorial behavior. In the present experiment we tested whether progesterone and testosterone could also play an activational role in the expression of adult aggressive behavior. We subjected post-reproductive male tree lizards to the following treatments: sham surgery, castration, castration with progesterone supplementation, and castration with testosterone supplementation. We measured several different dimensions of aggressive behavior. Overall in these post-reproductive animals, the level of aggression from lowest to highest was: castrates, shams, progesterone-treated, and testosterone-treated. Although testosterone appears to be the more potent regulator of aggressive behavior, progesterone enhanced several measures of aggression suggesting that it could play a role in natural regulation of aggressive behavior. This initial study used very high levels of progesterone (similar to or above those experienced by hatchlings) to maximize the probability of detecting an effect. Further studies are needed to determine if natural adult progesterone levels are sufficiently high to influence aggressive behavior.
睾酮通常被认为是调节脊椎动物成年雄性领地攻击性的主要性类固醇。然而，最近的证据表明，孕酮以及睾酮在树蜥（华丽角蜥）两种雄性生殖表型的组织形成中发挥作用，这两种表型在成年后的领地行为水平上有所不同。在本实验中，我们测试了孕酮和睾酮是否也能在成年攻击行为的表达中发挥激活作用。我们对繁殖后的雄性树蜥进行了以下处理：假手术、去势、补充孕酮的去势以及补充睾酮的去势。我们测量了攻击行为的几个不同维度。总体而言，在这些繁殖后的动物中，攻击水平从低到高依次为：去势动物、假手术动物、接受孕酮处理的动物和接受睾酮处理的动物。尽管睾酮似乎是攻击行为更有效的调节因子，但孕酮增强了多项攻击指标，这表明它可能在攻击行为的自然调节中发挥作用。这项初步研究使用了非常高的孕酮水平（类似于或高于幼体所经历的水平），以最大限度地提高检测到效果的可能性。需要进一步的研究来确定成年后自然的孕酮水平是否足够高以影响攻击行为。
