Blood leptin homeostasis:: sex-associated differences in circulating leptin levels in rats are independent of tissue leptin expression
Blood leptin homeostasis:: sex-associated differences in circulating leptin levels in rats are independent of tissue leptin expression
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DOI：
10.1016/s1357-2725(02)00092-4
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发表时间：
2003-01-01
影响因子：
4
通讯作者：
Palou, A
中科院分区：
文献类型：
--
作者：
Mulet, T;Picó, C;Palou, A
女性循环中的瘦素水平高于男性。本研究的目的是确定大鼠不同脂肪组织库（性腺、腹膜后、肠系膜和腹股沟白色脂肪组织和肩胛间棕色脂肪组织）中瘦素表达的性别相关差异的假定存在以及与循环瘦素水平的关系。使用适应22 ℃或28 ℃的成年雄性和雌性Wistar大鼠。采用北方印迹法检测瘦素mRNA表达，酶联免疫吸附试验（ELISA）检测血清瘦素水平。与人类的情况相反，我们在这里报告说，适应标准动物房条件（22 ℃）的雄性大鼠血液中的瘦素浓度高于雌性大鼠。这种情况不能用男性脂肪库的更大尺寸来解释，因为两种性别的肥胖指数相似，而是与白色脂肪组织的更高瘦素特异性mRNA表达相关。在热中性条件（28 ℃）附近，瘦素mRNA表达的性别相关差异消失，但循环瘦素水平的性别差异仍然存在。此外，瘦素mRNA的表达是较高的两种性别在热中性条件下，但这并没有反映在循环瘦素水平的变化。总之，这项研究表明，大鼠循环瘦素水平的精细调节，并不完全依赖于瘦素mRNA的表达，但也涉及其他机制，可能是关于瘦素降解率。(C)2002爱思唯尔科技有限公司版权所有。
Circulating leptin levels are higher in women than in men. The aim of the study has been to determine in rats the putative existence of sex-associated differences in leptin expression in different adipose tissue depots (gonadal, retroperitoneal, mesenteric and inguinal white adipose tissue and interscapular brown adipose tissue) and the relationship with circulating leptin levels. Adult male and female Wistar rats acclimated to 22degreesC or to 28degreesC were used. Leptin mRNA expression was assessed by northern blot and serum leptin levels by enzyme-linked immunosorbent assay (ELISA). Contrary to what happens in humans, we report here that male rats acclimated to standard animal house conditions (22degreesC) have a higher leptin concentration in blood than female rats. This situation cannot be explained by a greater size of the fat depots in males, because the adiposity index is similar in both genders, but are rather associated to higher leptin specific mRNA expression by the white adipose tissue. Around thermoneutral conditions (28degreesC), sex related differences in leptin mRNA expression disappear, but the gender difference in circulating leptin levels remains. In addition, leptin mRNA expression is higher in both genders in thermoneutral conditions but this is not reflected in changes in the circulating leptin levels. In conclusion, this study shows that rat circulating leptin levels are finely regulated, and not exclusively dependent on leptin mRNA expression, but other mechanisms are also involved, possibly regarding leptin rate of degradation. (C) 2002 Elsevier Science Ltd. All rights reserved.