Ziegler Toni E, Prudom Shelley L, Zahed Sofia Refetoff, Parlow A F, Wegner Fredrick
Wisconsin National Primate Research Center, University of Wisconsin, Madison, WI 53715, USA.
Horm Behav. 2009 Oct;56(4):436-43. doi: 10.1016/j.yhbeh.2009.07.012. Epub 2009 Aug 5.
Prolactin has been implicated in promoting paternal care behaviors but little evidence of causality has been found to date except for birds and fish. This study was designed to examine the possible causal relationships between prolactin and male parenting behaviors, reproductive hormones, and physical changes in cooperatively breeding common marmosets, Callithrix jacchus. Fifteen parentally experienced fathers were studied over three consecutive infant care periods during two weeks prior and three weeks following their mates' parturition under three-treatment conditions: normal control pregnancy, decreased prolactin and elevated prolactin. The treatments significantly altered the serum prolactin levels in the fathers. Using three methods of determining a father's level of parental care: infant carrying, family effort and responsiveness to infant stimulus tests, we found that only the male response to infant stimuli was altered by the hormone treatments. Lowering prolactin significantly reduced male responsiveness to infant stimuli but elevating prolactin showed the same effect. Hormonal sampling indicated that testosterone levels showed an inverse relationship to prolactin levels during a normal peripartum period and prolactin treatment reduced this relationship. Prepartum estradiol levels were significantly elevated during the lowered prolactin treatment and estradiol was significantly lowered postpartum with the elevated prolactin treatment. Father's weight decreased significantly by the third week of infant care during the normal treatment. Males in the elevated prolactin treatment lost little or no weight from prepartum while in the lowered prolactin treatment showed the most weight loss. The present findings did not distinguish a direct causal relationship of prolactin on behavior in experienced fathers but did find an interaction with other hormones and weight gain.
催乳素被认为与促进父性行为有关，但迄今为止，除了鸟类和鱼类外，几乎没有因果关系的证据。本研究旨在探讨催乳素与合作繁殖的普通狨猴（Callithrix jacchus）的雄性养育行为、生殖激素和身体变化之间可能的因果关系。在15只具有育儿经验的雄性狨猴的配偶分娩前两周和分娩后三周的三个连续婴儿护理期内，在三种处理条件下对它们进行了研究：正常对照妊娠、催乳素降低和催乳素升高。这些处理显著改变了雄性狨猴的血清催乳素水平。我们使用三种确定雄性狨猴育儿水平的方法：携带婴儿、家庭努力和对婴儿刺激测试的反应性，发现只有雄性对婴儿刺激的反应因激素处理而改变。降低催乳素显著降低了雄性对婴儿刺激的反应性，但升高催乳素也显示出相同的效果。激素采样表明，在正常围产期，睾酮水平与催乳素水平呈负相关，催乳素处理降低了这种关系。在降低催乳素处理期间，产前雌二醇水平显著升高，而在升高催乳素处理后，产后雌二醇水平显著降低。在正常处理期间，到婴儿护理的第三周，雄性狨猴的体重显著下降。在升高催乳素处理组中，雄性狨猴从产前到产后体重几乎没有减轻或没有减轻，而在降低催乳素处理组中体重减轻最多。目前的研究结果并未区分催乳素对有经验的雄性狨猴行为的直接因果关系，但确实发现了与其他激素和体重增加的相互作用。
