Duncan M J, Goldman B D
Am J Physiol. 1985 Jun;248(6 Pt 2):R664-7. doi: 10.1152/ajpregu.1985.248.6.R664.
The Djungarian hamster exhibits a dark agouti pelage during the summer. Under the influence of decreased daylength, this species molts and develops a predominantly white winter coat. After a patch of white fur was plucked from hamsters housed in short photoperiod, chronic infusion of 10 or 20 micrograms ovine prolactin (o-PRL)/day led to the growth of a patch of pigmented fur, thus reversing the effect of the decreased daylength. Circulating o-PRL levels produced by the 10-micrograms/day infusions ranged from 17.9 +/- 4.0 to 35.1 +/- 13.8 (SE) ng/ml and thus approximated the endogenous circulating prolactin levels found in hamsters with the dark summer pelage (6, 9). Infusion of o-PRL stimulated pigmentation of the pelage of castrated as well as intact hamsters, suggesting that the testes do not mediate this effect. Infusion of ovine growth hormone (20 micrograms/day) did not stimulate pigmentation, and infusion of alpha-melanocyte-stimulating hormone (10 micrograms/day) gave inconclusive results.
在夏季，黑线毛足鼠的毛色为深褐色。在日照时长缩短的影响下，该物种会脱毛并长出以白色为主的冬季皮毛。从处于短光照周期环境中的仓鼠身上拔下一片白色皮毛后，每天持续注入10或20微克的羊催乳素（o-PRL）会促使一片有色素的皮毛生长，从而逆转日照时长缩短的影响。每天注入10微克所产生的循环o-PRL水平在17.9±4.0至35.1±13.8（标准误）纳克/毫升之间，因此接近处于夏季深色皮毛状态的仓鼠体内的内源性循环催乳素水平（6, 9）。注入o-PRL会刺激去势仓鼠以及未去势仓鼠的皮毛色素沉着，这表明睾丸并不介导这种作用。注入羊生长激素（每天20微克）不会刺激色素沉着，而注入α-黑素细胞刺激素（每天10微克）的结果并不明确。
