Prenatal and early postnatal NOAEL-dose clothianidin exposure leads to a reduction of germ cells in juvenile male mice

The Journal of Veterinary Medical Science

Anzu YAMAMOTO¹  Shogo YANAI¹  Tetsushi HIRANO¹  Takuya OMOTEHARA¹  Tadashi TAKADA¹  Naoto KUBOTA¹  Naoki YONEDA¹  Nobuhiko HOSHI¹  Toshifumi YOKOYAMA¹  Youhei MANTANI²  Hiroshi KITAGAWA² 

[1] Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo 657-8501, Japan;Laboratory of Histophysiology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo 657-8501, Japan

关键词: blood-testis barrier;    clothianidin;    germ cell;    neonicotinoid;    prenatal and early postnatal exposure;   

DOI  :  10.1292/jvms.17-0154

学科分类：兽医学

来源: Japanese Society of Veterinary Science

【 摘 要 】

Neonicotinoids are pesticides used worldwide. They bind to insect nicotinic acetylcholine receptors (nAChRs) with high affinity. We previously reported that clothianidin (CTD), one of the latest neonicotinoids, reduced antioxidant expression and induced germ cell death in the adult testis of vertebrates. Here, we investigated the male reproductive toxicity of prenatal and early postnatal exposure to CTD, because it is likely that developmental exposure more severely affects the testis compared to adults due to the absence of the blood-testis barrier. Pregnant C57BL/6 mice were given water gel blended with CTD (0, 10 or 50 mg/kg/day; no-observed-adverse-effect-level [NOAEL for mice] 47.2 mg/kg/day) between gestational day 1 and 14 days post-partum. We then examined the testes of male offspring at postnatal day 14. The testis weights and the numbers of germ cells per seminiferous tubule were decreased in the CTD-50 group, and abnormal tubules containing no germ cells appeared. Nevertheless, the apoptotic cell number and proliferative activity were not significantly different between the control and CTD-exposed groups. There were no significant differences in the androgen-related parameters, such as the Leydig cell volume per testis, the Sertoli cell number and the tubule diameter. The present study is the first demonstration that in utero and lactational exposures to CTD at around the NOAEL for mice reduce the germ cell number, but our findings suggest that these exposures do not affect steroidogenesis in Leydig cells during prenatal or early postnatal life.

【 授权许可】

Unknown