Camihort Gisela, Luna Georgina, Vesenbeckh Silvan, Ferese Celia, Dardenne Mireille, Goya Rodolfo, Cónsole Gloria
Department of Cytology, Histology and Embryology B, University of La Plata-CICBA, La Plata, Argentina.
Cells Tissues Organs. 2006;184(1):23-30. doi: 10.1159/000096948.
Thymulin is a thymic hormone involved in several aspects of intra- and extrathymic T-cell differentiation. Thymulin also possesses hypophysiotropic activity which suggests that this metallopeptide may play an important role in thymus-pituitary communication, particularly during early life. The aim of the present study was to evaluate the impact of serum thymulin suppression from birth to peripuberty on the morphology of different pituitary cell populations in prepubertal C57Bl/6 mice. Animals were submitted to immunoneutralization of circulating thymulin from postnatal day 1 to the end of the study (age 32 days). From their 1st day of life, the animals were submitted to a protocol of intraperitoneal injections of rabbit anti-thymulin serum (alpha-FTS) and normal rabbit serum (NRS) in the controls. On their 33rd day of life, the animals were killed and their pituitaries were immediately dissected, fixed and immunostained using the EnVision system with primary antibodies against growth hormone, thyrotropin, corticotropin, gonadotropins and prolactin. Morphometry was performed by means of an image analysis system. The following parameters were calculated: volume density = Sigma cell area/reference area (RA); cell density (CD) = number of cells/RA, and cell size (expressed in microm2). Serum thymulin was measured by a rosette bioassay while pituitary hormones were assayed by radioimmunoassay. Serum prolactin, luteinizing hormone, follicle-stimulating hormone, growth hormone and thyroid-stimulating hormone were significantly lower in the alpha-FTS animals of either sex compared with the corresponding NRS counterparts. The somatotrope, lactotrope and corticotrope populations showed a significant decrease in CD, while cell hypertrophy was observed in some of the pituitary cell populations of the alpha-FTS group compared to the NRS group. In the alpha-FTS group, there were sex differences in the morphometric changes observed. Our results suggest that serum thymulin plays a significant role during early life in the postnatal maturation of endocrine cells of the mouse anterior pituitary gland.
胸腺素是一种胸腺激素，参与胸腺内和胸腺外T细胞分化的多个方面。胸腺素还具有促垂体活性，这表明这种金属肽可能在胸腺 - 垂体通讯中起重要作用，特别是在生命早期。本研究的目的是评估从出生到青春期前血清胸腺素抑制对青春期前C57Bl/6小鼠不同垂体细胞群形态的影响。从出生后第1天到研究结束（32天龄），对动物进行循环胸腺素的免疫中和。从出生第一天起，给动物按方案腹腔注射兔抗胸腺素血清（α-FTS），对照组注射正常兔血清（NRS）。在动物33天龄时，将其处死，立即解剖垂体，固定并用EnVision系统进行免疫染色，使用抗生长激素、促甲状腺激素、促肾上腺皮质激素、促性腺激素和催乳素的一抗。通过图像分析系统进行形态计量学分析。计算以下参数：体积密度=Σ细胞面积/参考面积（RA）；细胞密度（CD）=细胞数量/RA，细胞大小（以平方微米表示）。通过玫瑰花结生物测定法测量血清胸腺素，通过放射免疫测定法测定垂体激素。与相应的NRS组相比，α-FTS组的雌雄动物血清催乳素、黄体生成素、促卵泡激素、生长激素和促甲状腺激素均显著降低。生长激素细胞、催乳激素细胞和促肾上腺皮质激素细胞群的CD显著降低，而与NRS组相比，α-FTS组的一些垂体细胞群出现细胞肥大。在α-FTS组中，观察到的形态计量学变化存在性别差异。我们的结果表明，血清胸腺素在小鼠出生后早期垂体前叶内分泌细胞的成熟过程中起重要作用。
