Postnatal Development of the Testis in the Rat: Morphologic Study and Correlation of Morphology to Neuroendocrine Parameters
Postnatal Development of the Testis in the Rat: Morphologic Study and Correlation of Morphology to Neuroendocrine Parameters
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DOI：
10.1177/0192623314547279
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发表时间：
2015-04-01
影响因子：
1.5
通讯作者：
Parker, George A.
中科院分区：
文献类型：
--
作者：
Picut, Catherine A.;Remick, Amera K.;Parker, George A.
幼年大鼠睾丸的组织病理学检查通常是必要的，以确定儿童使用的新药的安全性，并且是男性青春期发育和甲状腺功能测试的必要终点。为了帮助评估和解释未成熟的睾丸，描述了发育中的大鼠睾丸在出生后整个发育过程中的组织学特征，并与已发表的神经内分泌参数变化进行了关联。在新生儿期(出生后3-7天)，曲细精管含有性细胞和有丝分裂活跃的未成熟支持细胞。婴儿早期(PND8-14)精原细胞大量增殖，支持细胞持续增殖。精原细胞密度在婴儿期末期(PND15-20)达到最大，与支持细胞形成双层花环。随着管腔的发育，细线期/合线期的精母细胞集中出现，单个小管分裂成不同的阶段。幼年期(PND 21-32)粗线型精母细胞的数量和大小急剧增加，形成圆形精细胞，失去婴儿的花环构型。在围青春期(PND 32-55)，在PND 46可见含有Step 19精子细胞的VII期小管。提供的基线形态和内分泌学信息将帮助病理学家区分发育延迟和异种生物效应，当遇到非特异性发现时确定发病机制，并为有针对性的研究设计确定敏感的时间点。
Histopathologic examination of the testis from juvenile rats is often necessary to characterize the safety of new drugs for pediatric use and is a required end point in male pubertal development and thyroid function assays. To aid in evaluation and interpretation of the immature testis, the characteristic histologic features of the developing rat testis throughout postnatal development are described and correlated with published neuroendocrine parameter changes. During the neonatal period (postnatal day [PND] 3-7), seminiferous tubules contained gonocytes and mitotically active immature Sertoli cells. Profound proliferation of spermatogonia and continued Sertoli cell proliferation occurred in the early infantile period (PND 8-14). The spermatogonia reached maximum density forming double-layered rosettes with Sertoli cells in the late infantile period (PND 15-20). Leptotene/zygotene spermatocytes appeared centrally as tubular lumina developed, and individual tubules segregated into stages. The juvenile period (PND 21-32) featured a dramatic increase in number and size of pachytene spermatocytes with the formation of round spermatids and loss of infantile rosette architecture. In the peri-pubertal period (PND 32-55), stage VII tubules containing step 19 spermatids were visible by PND 46. The presented baseline morphologic and endocrinologic information will help pathologists distinguish delayed development from xenobiotic effects, determine pathogenesis when confronted with nonspecific findings, and identify sensitive time points for targeted study design.