Brager D H, Sickel M J, McCarthy M M
Department of Physiology and Center for Studies in Reproduction, University of Maryland, School of Medicine, Baltimore, Maryland, 21201, USA.
J Neurobiol. 2000 Feb 15;42(3):315-22.
The proteins calbindin-D(28K) and calretinin buffer intracellular calcium and are speculated to be involved in the integration of neuronal signaling. Using Western blot analysis, we compared the levels of calbindin-D(28K) and calretinin in the developing male and female rat hypothalamus on postnatal days (PN) 0, PN2, PN4, PN6, PN8, and PN10. Analysis of variance (ANOVA) of mean calbindin levels indicated a significant effect of sex (p </=.001) and age (p </=. 0001) and a significant interaction (p </=.02). Post-hoc Neuman-Keuls analysis revealed that PN0 and PN2 males had significantly elevated calbindin levels over PN0 and PN2 females (p </=.05). ANOVA of mean calretinin levels from the same animals also indicated a significant effect of sex (p </=.002) and a significant interaction between sex and age (p </=.001). Post-hoc analysis indicated males had significantly elevated calretinin levels over PN0, PN4 (p </=.05) and PN6 (p </=.01) females. Immunocytochemical analyses indicated calbindin-immunopositive staining for cell bodies in the central subdivision of the medial preoptic nucleus, paraventricular nucleus, arcuate nucleus, and dorsomedial nucleus, and an area immediately surrounding the ventromedial nucleus (VMN). Calbindin immunoreactivity was absent from the ventrolateral VMN, but lightly stained cell bodies were observed in the dorsomedial VMN. The sex differences observed in calcium binding proteins parallel our previously observed sex differences in excitatory gamma-aminobutyric acid and glutamate early in development and may be related to mechanisms of sexual differentiation of the brain.
钙结合蛋白-D（28K）和钙视网膜蛋白可缓冲细胞内钙，并推测其参与神经元信号整合。我们采用蛋白质免疫印迹分析，比较了出生后第0天（PN0）、PN2、PN4、PN6、PN8和PN10的雄性和雌性大鼠发育中的下丘脑内钙结合蛋白-D（28K）和钙视网膜蛋白的水平。钙结合蛋白平均水平的方差分析（ANOVA）表明，性别（p≤0.001）和年龄（p≤0.0001）有显著影响，且存在显著交互作用（p≤0.02）。事后纽曼-凯尔斯分析显示，PN0和PN2的雄性大鼠的钙结合蛋白水平显著高于PN0和PN2的雌性大鼠（p≤0.05）。对同一批动物的钙视网膜蛋白平均水平进行的方差分析也表明，性别有显著影响（p≤0.002），且性别与年龄之间存在显著交互作用（p≤0.001）。事后分析表明，雄性大鼠的钙视网膜蛋白水平显著高于PN0、PN4（p≤0.05）和PN6（p≤0.01）的雌性大鼠。免疫细胞化学分析表明，在内侧视前核中央亚区、室旁核、弓状核和背内侧核以及腹内侧核（VMN）周围的区域，细胞体有钙结合蛋白免疫阳性染色。腹外侧VMN没有钙结合蛋白免疫反应性，但在背内侧VMN观察到细胞体有轻度染色。在钙结合蛋白中观察到的性别差异与我们之前在发育早期观察到的兴奋性γ-氨基丁酸和谷氨酸中的性别差异相似，可能与大脑性分化机制有关。
