Photoperiodic and hormonal influences on fur density and regrowth in two hamster species
Photoperiodic and hormonal influences on fur density and regrowth in two hamster species
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DOI：
10.1152/ajpregu.00520.2007
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发表时间：
2007-12-01
影响因子：
2.8
通讯作者：
Butler, Matthew P.
中科院分区：
文献类型：
--
作者：
Paul, Matthew J.;George, Nicole T.;Butler, Matthew P.
温带和北方哺乳动物的毛皮经历了季节性的变化，这有助于冬季和夏季的体温调节。我们研究了光周期对西伯利亚和叙利亚雄性仓鼠毛皮特征的影响。皮毛密度(mg毛皮/cm(2)皮肤)是通过称量从长日照(LDS)或转移到短日照(SDS)的仓鼠背部和腹面表面去除的皮片的碎屑来测量的。3wk后修复斑块以评估毛皮再生(mg再生毛皮/厘米(2)皮肤)。差异光处理11wk后，SD仓鼠的皮毛密度高于LD西伯利亚仓鼠。毛皮密度增加的开始伴随着毛皮再生的一过性增加(背部11-14wk，腹面7wk-10wk和11-14wk)，提示有季节性的蜕皮过程。西伯利亚仓鼠的毛皮密度、体质量和毛皮颜色在经过类似持续时间的长时间(27周)SD处理后，恢复到LD雄性仓鼠的特征值，并且似乎受到类似或共同的间隔时间机制的调节。在叙利亚仓鼠中，SD组的背部皮毛密度、毛皮再生和毛发长度大于LD组雄性仓鼠。去势增加和睾酮(T)处理减少了LD和SD仓鼠背部和腹侧毛皮的再生，但T操作对毛皮密度的影响仅限于T处理后背部毛皮密度的减少。SDS中循环T的降低可能通过增加雄性仓鼠在向冬季毛皮过渡期间的毛皮生长速度来促进季节性蜕皮。
Temperate and boreal mammals undergo seasonal changes in pelage that facilitate thermoregulation in winter and summer. We investigated photoperiodic influences on pelage characteristics of male Siberian and Syrian hamsters. Fur density (mg fur/cm(2) skin) was measured by weighing the shavings of fur patches removed from the dorsal and ventral surfaces of hamsters maintained in long days (LDs) or transferred to short days (SDs). Patches were reshaved 3 wk later to assess fur regrowth (mg regrown fur/cm(2) skin). Fur density was greater in SD than in LD Siberian hamsters after 11 wk of differential phototreatment. The onset of increased fur density in SDs was accompanied by a transient increase in fur regrowth (11-14 wk on the dorsal surface and 7-10 and 11-14 wk on the ventral surface), suggestive of a seasonal molting process. Fur density, body mass, and pelage color of Siberian hamsters returned to values characteristic of LD males after a similar duration of prolonged (> 27 wk) SD treatment and appear to be regulated by a similar or common interval-timing mechanism. In Syrian hamsters, dorsal fur density, fur regrowth, and hair lengths were greater in SD than in LD males. Castration increased and testosterone (T) treatment decreased dorsal and ventral fur regrowth in LD and SD hamsters, but the effects of T manipulations on fur density were limited to a decrease in dorsal fur density after T treatment. Decreased circulating T in SDs likely contributes to the seasonal molt of male hamsters by increasing the rate of fur growth during the transition to the winter pelage.