卵巢切除术可独立于大鼠视黄醇浓度的性别差异增加循环视黄醇结合蛋白浓度。

Ovariectomy Increases Circulating Retinol-Binding Protein Concentrations Independently of Sex-Dependent Differences in Retinol Concentrations in Rats.

作者信息

Moriya Hiroko, Yokobori Yuki, Furukawa Taichi, Kato Taku, Sato Ryota, Takenaka Asako

机构信息

Department of Agricultural Chemistry, School of Agriculture, Meiji University, Kawasaki, Kanagawa, Japan.

出版信息

J Nutr. 2023 Apr;153(4):1019-1028. doi: 10.1016/j.tjnut.2023.02.033. Epub 2023 Mar 2.

DOI:10.1016/j.tjnut.2023.02.033

PMID:36870537

Abstract

BACKGROUND

There is a sex-dependent difference in blood retinol and RBP concentrations, and plasma RBP is associated with insulin resistance.

OBJECTIVES

We aimed to clarify sex-dependent variations in body concentrations of retinol and RBPs and their association with sex hormones in rats.

METHODS

Plasma and liver retinol concentrations and hepatic mRNA and plasma concentrations of RBP4 were analyzed in 3- and 8-wk-old male and female Wistar rats before and after sexual maturity (experiment 1) and in orchiectomized male Wistar rats (experiment 2) and ovariectomized female Wistar rats (experiment 3). Furthermore, the mRNA and protein concentrations of RBP4 in adipose tissue were measured in ovariectomized female rats (experiment 3).

RESULTS

There were no sex-dependent differences in liver retinyl palmitate and retinol concentrations; however, the plasma retinol concentration was significantly higher in male rats than that in female rats after sexual maturity. Furthermore, the plasma retinol concentrations did not differ between the ovariectomized or orchiectomized rats and the control rats. Plasma Rbp4 mRNA concentrations were higher in male rats than those in female rats but not in castrated and control rats, a change consistent with plasma retinol concentration. Plasma RBP4 concentrations were also higher in male rats than those in female rats; however, unlike liver Rbp4 gene expression, plasma RBP4 concentrations were 7-fold higher in the ovariectomized rats than those in the control rats. Moreover, the Rbp4 mRNA concentrations in inguinal white adipose tissue was significantly higher in the ovariectomized rats than those in the control rats and correlated with plasma RBP4 concentrations.

CONCLUSIONS

Hepatic Rbp4 mRNA is higher in male rats through a sex hormone-independent mechanism, which may contribute to sex differences in blood retinol concentrations. Furthermore, ovariectomy leads to an increase in adipose tissue Rbp4 mRNA and blood RBP4 concentrations, which may contribute to insulin resistance in ovariectomized rats and postmenopausal women.

摘要

背景

血液中视黄醇和视黄醇结合蛋白（RBP）浓度存在性别差异，且血浆RBP与胰岛素抵抗相关。

目的

我们旨在阐明大鼠体内视黄醇和RBPs浓度的性别差异及其与性激素的关系。

方法

对3周龄和8周龄性成熟前后的雄性和雌性Wistar大鼠（实验1）、去势雄性Wistar大鼠（实验2）和去势雌性Wistar大鼠（实验3）的血浆和肝脏视黄醇浓度以及肝脏RBP4的mRNA和血浆浓度进行分析。此外，在去势雌性大鼠中测量脂肪组织中RBP4的mRNA和蛋白浓度（实验3）。

结果

肝脏棕榈酸视黄酯和视黄醇浓度不存在性别差异；然而，性成熟后雄性大鼠的血浆视黄醇浓度显著高于雌性大鼠。此外，去势大鼠和对照大鼠的血浆视黄醇浓度没有差异。雄性大鼠的血浆Rbp4 mRNA浓度高于雌性大鼠，但去势大鼠和对照大鼠无差异，这一变化与血浆视黄醇浓度一致。雄性大鼠的血浆RBP4浓度也高于雌性大鼠；然而，与肝脏Rbp4基因表达不同，去势大鼠的血浆RBP4浓度比对照大鼠高7倍。此外，去势大鼠腹股沟白色脂肪组织中的Rbp4 mRNA浓度显著高于对照大鼠，且与血浆RBP4浓度相关。