Female infertility in carnitine-deficient mice: focus on the relationship between fatty acid toxicity and social stress vulnerability.

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K10430
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 58020:Hygiene and public health-related: including laboratory approach
• Research Institution: Kagoshima University
• Principal Investigator: Ushikai Miharu 鹿児島大学, 医歯学域医学系, 助教 (70232816)
• Co-Investigator(Kenkyū-buntansha): 堀内 正久 鹿児島大学, 医歯学域医学系, 教授 (50264403) ; 川口 博明 北里大学, 獣医学部, 教授 (60325777)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 不妊 / 脂肪酸代謝異常 / カルニチン / ストレス脆弱性

Outline of Final Research Achievements

In this study, we analyzed female infertility focusing on social stress vulnerability in the juvenile visceral steatosis (JVS) mice with carnitine deficiency. To understand the influence of the sex hormones on the infertility, the change of body weight, food intake, water intake, and locomotor activity under a running wheel was measured as a noninvasive measure related to the estrus cycle in female mice. Female JVS mice showed a trend toward weight loss due to decreased food intake under the condition from group-rearing to single-rearing, one of the social stresses. We also evaluated urinary catecholamine and blood hormone levels (corticosterone and estrogen) of group-rearing wild type and JVS mice to examine the relationship between fatty acid metabolism abnormality caused by carnitine deficiency and stress vulnerability. As a result, female JVS mice were suggested to be more susceptible to social stress than male JVS mice.

Free Research Field

衛生学

Academic Significance and Societal Importance of the Research Achievements

不妊の原因は様々であり、妊娠過程のどこに起因するかは不明な点も多く、男性・女性それぞれに妊孕性の評価が行われている。病態に応じた最適な介入法の開発のために、内的要因と外的要因の関与を明らかにすることが求められる。本研究で得られた知見から、脂肪酸代謝異常モデルマウスの雌性不妊は、内的要因（脂肪酸代謝異常）に外的要因（ストレス）が加わることにより発症する不妊病態の存在を明らかにする。また、脂肪酸代謝障害の病態に雌雄差の存在することを示すことになり、脂肪酸代謝障害の新たな側面を明らかにする基盤的研究となる。