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ID 113354
Title Alternative
生後早期の免疫ストレスによる成長後の性行動の低下は、血中アンドロゲン濃度の低下と無関係に起きる
Author
Mayila, Yiliyasi Tokushima University
Tungalagsuvd, Altankhuu Tokushima University|National Center for Maternal and Child Health
Munkhzaya, Munksaihan Tokushima University|The General Hospital for State Special Servants of Mongolia
Yano, Kiyohito Tokushima University
Yanagihara, Rie Tokushima University
Tokui, Takako Tokushima University
Keywords
Immune stress
Lipopolysaccharide
Progesterone receptor
Sexual behavior
Sexual maturation
Testosterone
Content Type
Thesis or Dissertation
Description
Purpose: It is known that various types of stress in early life increase the incidence of diabetes, myocardial infarctions, and psychiatric disorders in adulthood. We examined the mechanism by which neonatal immune stress reduces sexual behavior in adult male rats.
Methods: Male rats were randomly divided into 3 groups: the control (n=17), postnatal day 10 lipopolysaccharide (PND10LPS) (n=31), and PND25LPS (n=16) groups, which received intraperitoneal injections of LPS (100 μg/kg) or saline (injection volume: ≤0.1 ml/g) on postnatal days 10 and 25. In experiment 1, male rats (age: 11 to 12 weeks) were put together with female rats in a one-to-one setting for mating, and sexual behavior (mounting, intromission, and ejaculation) was monitored for 30 minutes. The serum levels of luteinizing hormone (LH) and testosterone (T) and the hypothalamic mRNA expression levels of factors related to sexual behavior were examined. After experiment 1 finished, the remaining 37 male rats were used for experiment 2: the control group (n=8), PND10 LPS group (n=21) and PND25LPS group (n=8) these rats had been given an i.p. injection of the saline during the expriment1. All of the rats were orchidectomized at 14 weeks of age. After a 3 week recovery period, a silastic tube containing crystalline T was subcutaneously implanted into the back of each rat. The rats’ sexual behavior, serum hormone concentrations, and hypothalamic mRNA expression levels were assessed.
Results: In experiment 1, preputial separation occurred significantly later in the PND10LPS group than in the control group. The frequency of sexual behavior was significantly lower in the PND10LPS group than in the control group. The serum T concentrations of the PND10LPS and PND25LPS groups were significantly lower than that of the control group, but the serum LH concentrations of the 3 groups did not differ significantly. The hypothalamic mRNA expression levels of progesterone receptor B (PRB) and gonadotropin-releasing hormone (GnRH) were significantly lower in the PND10LPS and PND25LPS groups than in the control group, whereas the hypothalamic PRA+B mRNA expression levels of the 3 groups did not differ significantly. In experiment 2, after T supplementation the frequency of sexual behavior was significantly lower in the PND10LPS and PND25LPS groups than in the control group, although there were no significant differences in the serum T or LH concentrations or the hypothalamic PRB, PRA+B, or GnRH mRNA expression levels of the 3 groups.
Conclusion: In male rats, immune stress in the early neonatal period delayed sexual maturation, reduced sexual behavior, suppressed the serum T concentration, and downregulated the hypothalamic mRNA expression levels of GnRH and the PR in adulthood. The delayed sexual maturation was presumed to have been caused by the reduction in the serum T concentration. However, the rats that experienced neonatal stress exhibited reduced sexual behavior irrespective of their serum T concentrations.
Journal Title
International Journal of Developmental Neuroscience
ISSN
07365748
NCID
AA11531026
Publisher
Elsevier|International Society for Developmental Neuroscience
Volume
71
Start Page
163
End Page
171
Published Date
2018-08-18
Remark
内容要旨・審査要旨・論文本文の公開
本論文は, 著者Yiliyasi Mayilaの学位論文として提出され, 学位審査・授与の対象となっている。
EDB ID
DOI (Published Version)
URL ( Publisher's Version )
FullText File
language
eng
TextVersion
ETD
MEXT report number
甲第3259号
Diploma Number
甲医第1408号
Granted Date
2019-03-22
Degree Name
Doctor of Medical Science
Grantor
Tokushima University
departments
Medical Sciences
University Hospital