Saha S K, Ohinata H, Kuroshima A
Department of Physiology I, Asahikawa Medical College, Japan.
Jpn J Physiol. 1996 Oct;46(5):375-82. doi: 10.2170/jjphysiol.46.375.
This study was undertaken to examine the possible role of nitric oxide (NO) on brown adipose tissue (BAT) thermogenesis in rats. The chronic administration of N omega-nitro-L-arginine methyl ester (L-NAME; NO synthase inhibitor) in drinking water given to rats decreased interscapular BAT (IBAT) weight as well as DNA content in a warm environment (25 +/- 1 degrees C; 2 and 4 weeks), and inhibited the cold-stimulated (5 +/- 1 degrees C; 2 weeks) increase in IBAT weight and DNA content. L-Arginine administration (4 weeks in a warm environment) increased the DNA content of IBAT. Chronic L-NAME administration (2 weeks in a warm environment) eliminated the NE-stimulated increase in in vivo oxygen consumption (VO2), caused hypothermia in acute cold exposure (0 degree C), and suppressed the NE-stimulated increase in in vitro IBAT VO2. In vitro incubation of native IBAT with L-NAME suppressed the basal and NE-stimulated increase in in vitro VO2. In vitro incubation of IBAT with methylene blue (soluble guanylate cyclase inhibitor and a scavenger of free NO) eliminated the NE-stimulated increase in in vitro IBAT VO2. These results suggest that the nitric oxide and NO-cGMP signaling systems are involved in the regulation of BAT cellularity and thermogenesis in rats.
本研究旨在探讨一氧化氮（NO）在大鼠棕色脂肪组织（BAT）产热过程中可能发挥的作用。给大鼠饮用含Nω-硝基-L-精氨酸甲酯（L-NAME；一氧化氮合酶抑制剂）的水，长期给药可使大鼠在温暖环境（25±1℃；2周和4周）下肩胛间棕色脂肪组织（IBAT）重量及DNA含量降低，并抑制冷刺激（5±1℃；2周）引起的IBAT重量和DNA含量增加。给予L-精氨酸（在温暖环境中4周）可增加IBAT的DNA含量。长期给予L-NAME（在温暖环境中2周）可消除去甲肾上腺素（NE）刺激引起的体内耗氧量（VO2）增加，在急性冷暴露（0℃）时导致体温过低，并抑制NE刺激引起的体外IBAT的VO2增加。用L-NAME对天然IBAT进行体外孵育可抑制基础状态下以及NE刺激引起的体外VO2增加。用亚甲蓝（可溶性鸟苷酸环化酶抑制剂和游离NO清除剂）对IBAT进行体外孵育可消除NE刺激引起的体外IBAT的VO2增加。这些结果表明，一氧化氮和NO-环鸟苷酸信号系统参与了大鼠棕色脂肪组织细胞数量及产热的调节。
