Korac Aleksandra, Buzadzic Biljana, Petrovic Vesna, Vasilijevic Ana, Jankovic Aleksandra, Korac Bato
Faculty of Biology, University of Belgrade, Belgrade, Serbia.
Folia Histochem Cytobiol. 2008;46(1):103-9. doi: 10.2478/v10042-008-0015-6.
The aim of the present study was to explore the effect of nitric oxide on leptin immunoexpression and innervation in interscapular brown adipose tissue (IBAT) of room- and cold- acclimated rats. Animals acclimated both to room-temperature (22 +/- 1 degrees C) and cold (4 +/- 1 degrees C) were treated with L-arginine, a substrate for nitric oxide synthases (NOSs), or N?-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NOSs, for 45 days. Leptin expression and localization in brown adipocytes was studied by immunohistochemistry, and innervation stained by the Bodian method. Strong leptin immunopositivity was observed in brown adipocytes cytoplasm of all room-acclimated groups, but nuclear leptin positivity was found only in L-NAME treated rats. In cold-acclimated control and L-NAME treated rats leptin immunopositivity was absent, while L-arginine treatment reversed the cold-induced suppression of leptin expression. Comparing to control, L-arginine, and even more L-NAME, at 22 +/- 1 degrees C induced greater innervation. In conclusion, L-arginine treatment changes leptin expression pattern on cold in rat IBAT.
本研究的目的是探讨一氧化氮对室温适应和冷适应大鼠肩胛间棕色脂肪组织（IBAT）中瘦素免疫表达和神经支配的影响。将适应室温（22±1℃）和寒冷（4±1℃）的动物用一氧化氮合酶（NOSs）的底物L-精氨酸或NOSs的抑制剂Nω-硝基-L-精氨酸甲酯（L-NAME）处理45天。通过免疫组织化学研究棕色脂肪细胞中瘦素的表达和定位，并用博迪安法对神经支配进行染色。在所有室温适应组的棕色脂肪细胞胞质中均观察到强瘦素免疫阳性，但仅在L-NAME处理的大鼠中发现核瘦素阳性。在冷适应对照和L-NAME处理的大鼠中，瘦素免疫阳性缺失，而L-精氨酸处理逆转了冷诱导的瘦素表达抑制。与对照组相比，在22±1℃时，L-精氨酸，甚至更多的L-NAME诱导了更强的神经支配。总之，L-精氨酸处理改变了大鼠IBAT在寒冷条件下的瘦素表达模式。
