SEXUAL DIMORPHISM AND ANDROGEN EFFECTS ON SPINAL MOTONEURONS INNERVATING THE RAT FLEXOR DIGITORUM BREVIS
SEXUAL DIMORPHISM AND ANDROGEN EFFECTS ON SPINAL MOTONEURONS INNERVATING THE RAT FLEXOR DIGITORUM BREVIS
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DOI：
10.1016/0006-8993(91)91603-x
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发表时间：
1991-10-11
期刊：
影响因子：
2.9
通讯作者：
BREEDLOVE, SM
中科院分区：
文献类型：
--
作者：
LESLIE, M;FORGER, NG;BREEDLOVE, SM
大鼠足肌趾短屈肌受腰髓背外侧后核运动神经元支配。 我们发现这肌肉是性二态的，但不敏感的合成代谢或分解代谢的雄激素操纵的影响，在成年雄性大鼠的趾短屈肌比雌性大鼠大，与去势后的男性质量没有减少，也没有任何增加后的大小雄激素治疗卵巢切除的女性。 支配该肌肉的运动神经元的横截面积也是两性异形的，即，雄性运动神经元较大。 然而，与雄激素对目标肌肉大小无影响相反，去势导致成年男性运动神经元的横截面积减少，雄激素治疗后成年女性运动神经元的横截面积增加。 雄激素对肌肉质量和运动神经元大小的影响的分离表明，类固醇对运动神经元的影响可能独立于对靶肌肉组织的影响。
The foot muscle, flexor digitorum brevis, is innervated by motoneurons in the retrodorsolateral nucleus of the lumbar spinal cord in rats. We found this muscle to be sexually dimorphic, but insensitive to the anabolic or catabolic effects of androgen manipulation in adulthood: the flexor digitorum brevis was larger in adult male rats than in females, with no decrease in mass after castration in males nor any increase in size after androgen treatment of ovariectomized females. The cross-sectional area of motoneurons innervating this muscle was also sexually dimorphic, i.e., the motoneurons were larger in males. In contrast to the absence of an androgen effect on target muscle size, however, cross-sectional area of motoneurons decreased in adult males as a result of castration, and increased in adult females after androgen treatment. The dissociation of androgen effects on muscle mass and motoneuron size suggests the possibility of steroid effects upon motoneurons independent of effects upon target musculature.