title: [Effects of cypermethrin exposure during lactation of female mice on testicular steroidogenesis in male baby mice].
abstract: OBJECTIVE
  To discuss the influence on the testicular steroidogenesis synthesation during baby mice cut-milking period and adult period of male mice by the cypermethrin exposure during lactation of the female mice.
  
  
  METHODS
  Fourteen dams of new-born mice were randomly divided into two groups, cypermethrin poisoning group and solution control group. Since the first day after baby delivery, the aternal mice in the cypermethrin poisoning group were given stomach cypermethrin poisoning, using the corn oil as the solution and the poison dose is 25mg! kg, until the 21st day after the delivery when the baby mice has cut-milking. While the control group is given the gavagy of the corn oil of the same volume. In each group, 15 male baby mice were killed at 21st day and 70th day after delivery, respectively. Taking blood from the eye-balls, and separate the testes. Use radioimmunoassay (LIlA) method to measure serum testosterone (T) and estrogen (E2) levels. Use RT-PCR method to measure StAR in the testes and the mRNA expression level of testosterone synthetic enzymes. Use Western blot to measure StAR in the testes and the protein expression level of testosterone synthetic enzymes.
  
  
  RESULTS
  Cypermethrin exposure during lactation of the female mice significantly leads to the decrease of serum testosterone of the male baby mice (P < 0.01) and the decrease of the testosterone in the testes (P < 0.05), having no influence of the female hormones (P < 0.05). And the cypermethrin exposure during lactation makes the significant decrease of the expression levels of the mRNA and the protein, of P450scc in the male baby mice testes, compared with the control group. And the mRNA expression levels of StAR, 17beta-HSD, and P450 17alpha decrease somewhat (P < 0.05), compared with the control group, but the protein expression levels of the above almost suffer no influence. Cypermethrin exposure during lactation of the female mice has almost no influence on the serum testosterone level, testosterone level in the testes, the StAR in the testes, and the expression levels of mRNA and protein of the testosterone synthetic enzymes (P > 0.05).
  
  
  CONCLUSIONS
  Cypermethrin exposure during lactation may influence testosterone biosynthesis in the testes of the 21 days male baby mice, mainly by down-modulating mRNA and protein expression levels of testicular P450scc.
authors.affiliation: School of Public Health, Anhui Medical University, Hefei 230032, China. wangsufangdev@126.com
authors.forename: Sufang
authors.initials: S
authors.lastname: Wang
authors.forename: Xinghao
authors.initials: X
authors.lastname: Ma
authors.forename: Huan
authors.initials: H
authors.lastname: Ning
authors.forename: Min
authors.initials: M
authors.lastname: Mu
authors.forename: Yanmei
authors.initials: Y
authors.lastname: Wan
authors.forename: Dexiang
authors.initials: D
authors.lastname: Xu
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D004958:Estradiol / Q000097:blood; D005260:Female; D007306:Insecticides / Q000633:toxicity; D007774:Lactation; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects*; D051379:Mice; D008813:Mice, Inbred ICR; D010750:Phosphoproteins / Q000378:metabolism; D011722:Pyrethrins / Q000633:toxicity*; D013737:Testis / Q000187:drug effects* / Q000378:metabolism; D013739:Testosterone / Q000096:biosynthesis* / Q000097:blood; D000098682:Steroidogenic Acute Regulatory Protein
chemical_list: D007306:Insecticides; D010750:Phosphoproteins; D011722:Pyrethrins; D000098682:Steroidogenic Acute Regulatory Protein; C017160:cypermethrin; D013739:Testosterone; D004958:Estradiol