Centre d'Etudes Biologiques de Chizé, CNRS, 79360 Villiers en Bois, France.
Gen Comp Endocrinol. 2013 Feb 1;182:7-15. doi: 10.1016/j.ygcen.2012.10.008. Epub 2012 Nov 7.
Over the last decades, the corticosterone stress response has been suggested as a major physiological tool to understand what strategy an individual might adopt in response to environmental perturbations. More recently, another hormone related to parental care--prolactin--has been suggested as a complementary tool to investigate this question. Indeed, both of these hormones are affected by stressors and are involved in parental decisions, such as deserting the nest. Because of these similarities, it remains unclear what the functional distinction between the prolactin and corticosterone stress responses is. Here, we investigated whether natural variations of the corticosterone and prolactin stress responses are functionally linked in free-living Cape petrel (Daption capense) parents. If prolactin and corticosterone mediate the same functional response to a stressor and are the proxies of the same response, we predict that corticosterone and prolactin stress responses (1) will be modulated according to the same factors; (2) will affect reproductive performances in the same way; and, (3) of course, will be correlated. Contrary to these predictions, we found that the corticosterone and prolactin stress responses were respectively modulated according to body condition and breeding status. Moreover, prolactin levels, but not corticosterone levels, were related to hatching success in this species. Finally, we did not find any significant correlation between these two stress responses under any circumstances (failed breeders, incubating or chick rearing birds) and this result was overall supported by a review of the existing literature. Therefore, these two stress responses do not seem to be tightly linked and we believe that they may provide complementary pieces of information on parental investment in birds.
在过去的几十年里，皮质酮应激反应被认为是理解个体可能采取何种策略应对环境干扰的主要生理工具。最近，另一种与亲代抚育有关的激素——催乳素——也被认为是研究这一问题的补充工具。事实上，这两种激素都受到应激源的影响，并参与亲代决策，如弃巢。由于这些相似性，皮质酮和催乳素应激反应之间的功能区别仍然不清楚。在这里，我们研究了游离生活的海角海燕（Daption capense）亲代的皮质酮和催乳素应激反应的自然变化是否在功能上相关。如果催乳素和皮质酮介导对同一应激源的相同功能反应，并且是同一反应的代表，我们预测皮质酮和催乳素应激反应（1）将根据相同的因素进行调节；（2）将以相同的方式影响繁殖表现；并且（3）当然，将相关。与这些预测相反，我们发现皮质酮和催乳素应激反应分别根据身体状况和繁殖状况进行调节。此外，在该物种中，催乳素水平而不是皮质酮水平与孵化成功率有关。最后，我们在任何情况下（未繁殖的、孵化或育雏的鸟类）都没有发现这两种应激反应之间存在任何显著相关性，这一结果得到了现有文献综述的支持。因此，这两种应激反应似乎没有紧密联系，我们认为它们可能为鸟类的亲代投资提供补充信息。
