The aim of this study was to investigate carnitine action against negative effects of etoposide on stem/progenitor spermatogonia and on sperm production. Carnitine (250 mg/kg body weight/day) and etoposide (5 mg/kg body weight/day) were administered from 25-days postpartum to 32-days postpartum. Testes were collected at 32-days postpartum, 64-days postpartum, and 127-days postpartum, and submitted to the immuno-labeling of UTF1, SOX2, and PLZF proteins to identify undifferentiated spermatogonia populations. At 127-days postpartum, sperm were collected for analysis. Carnitine+etoposide group showed a higher numerical density of spermatogonia labeled for all studied proteins at 64-days postpartum (critical age) compared to the etoposide group. Moreover, there was an improvement of spermatic parameters and sperm DNA integrity in rats of the carnitine+etoposide group in comparison with rats of the etoposide group. The results suggest that carnitine improves the self-renewal of undifferentiated spermatogonia and promotes a partial protection on them, alleviating the etoposide harmful late effects and leading to an enhancement of the sperm parameters in adulthood.

中文翻译：

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肉碱减少青春期前对成年大鼠精原细胞自我更新和精子产生的依托泊苷的毒性作用。

这项研究的目的是研究肉碱对依托泊苷对茎/祖精原细胞和精子产生的负面影响的作用。从产后25天到产后32天服用肉碱（250 mg / kg体重/天）和依托泊苷（5 mg / kg体重/天）。在产后32天，产后64天和产后127天收集睾丸，并对其进行UTF1，SOX2和PLZF蛋白的免疫标记，以鉴定未分化的精原细胞群。产后127天，收集精子进行分析。与依托泊苷组相比，肉碱+依托泊苷组在产后64天（临界年龄）显示出所有研究蛋白质标记的精原细胞数量密度更高。此外，肉毒碱+依托泊苷组的大鼠与依托泊苷组的大鼠相比，精子参数和精子DNA完整性得到改善。结果表明，肉碱可改善未分化精原细胞的自我更新，并促进对它们的部分保护，减轻依托泊苷的有害后期效应，并导致成年期精子参数提高。