CATECHOLAMINERGIC INNERVATION OF WHITE ADIPOSE-TISSUE IN SIBERIAN HAMSTERS
CATECHOLAMINERGIC INNERVATION OF WHITE ADIPOSE-TISSUE IN SIBERIAN HAMSTERS
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DOI：
10.1152/ajpregu.1995.268.3.r744
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发表时间：
1995-03-01
影响因子：
2.8
通讯作者：
BARTNESS, TJ
中科院分区：
文献类型：
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作者：
YOUNGSTROM, TG;BARTNESS, TJ
当西伯利亚仓鼠从长夏日(LDS)转变为短冬日(SDS)时，它们的体重会减少，主要是作为身体脂肪。这些由SD引起的脂肪储存的减少并不是一致的。位于内部的白色脂肪组织(WAT)垫优先消耗脂肪，而位于较外部的皮下WAT垫相对较少。这些数据提示对儿茶酚胺诱导的脂解可能有不同的交感神经控制，内垫比外垫的脂解率更高。此外，如果这些不同的脂解率是由于垫上不同的交感神经系统(SNS)驱动，那么脂肪垫特异性的儿茶酚胺能神经可能存在。因此，我们测试了腹股沟Wat(IWAT；外垫)和附睾Wat(EWAT；内垫)是否有不同的神经支配。此外，我们测试了去甲肾上腺素(NE)周转率(TO)是否反映了SD暴露后EWAT与IWAT之间推定的更大的SNS驱动力。注射荧光束示踪剂[荧光金或吲哚碳蓝高氯酸盐(DII)]显示从三叉神经节T-13-L(3)向双侧脂肪垫的投射。逆行标记显示了投射到每个垫的神经节中标记神经元的相对独立的分布模式。在体内，DiI的顺行运输导致了IWAT和EWAT的标记，包括在单个脂肪细胞周围染色，有时还会逆行标记细胞。在SD暴露5周后，与IWAT质量相比，EWAT质量的比例更大的下降反映在EWAT NE to比其LD对应的Ld更大。在SD暴露10wk后，EWAT和TAT中的NE to均显著高于其LD同种异物。总而言之，这些结果表明，在暴露于十二烷基硫酸钠的西伯利亚仓鼠中，脂肪垫质量的差异变化是一种神经机制。综上所述，本研究首次为啮齿动物SNS对WAT和EWAT的神经支配提供了直接的解剖学证据。此外，这些数据支持了传统上被忽视的Wat的SNS神经支配的重要作用。
When Siberian hamsters are transferred from long summerlike days (LDs) to short winterlike days (SDs) they decrease their body weight, primarily as body fat. These SD-induced decreases in lipid stores are not uniform. Internally located white adipose tissue (WAT) pads are depleted preferentially of lipid, whereas the more externally located subcutaneous WAT pads are relatively spared. These data suggest a possible differential sympathetic neural control over catecholamine-induced lipolysis and that lipolytic rates are greater for internal vs. external WAT pads. Moreover, if these differential rates of lipolysis are due to differential sympathetic nervous system (SNS) drives on the pads, then fat pad-specific catecholaminergic innervation may exist. Therefore, we tested whether inguinal WAT (IWAT; an external pad) and epididymal WAT (EWAT; an internal pad) were innervated differentially. In addition, we tested whether norepinephrine (NE) turnover (TO) reflected the presumed greater SNS drive on EWAT vs. IWAT after SD exposure. Injections of fluorescent tract tracers [Fluoro-Gold or indocarbocyanine perchlorate (DiI)] demonstrated projections from the SNS ganglia T-13-L(3) to both fat pads. Retrograde labeling revealed a relatively separate pattern of distribution of labeled neurons in the ganglia projecting to each pad. In vivo anterograde transport of DiI resulted in labeling in both IWAT and EWAT that included staining around individual adipocytes and occasionally retrogradely labeled cells. The proportionately greater decrease in EWAT compared with IWAT mass after 5 wk of SD exposure was reflected in greater EWAT NE TO than found in their LD counterparts for this pad. After 10 wk of SD exposure, NE TO in both EWAT and TWAT is elevated significantly vs. that of their LD conspecifics. Collectively, these results suggest a neural mechanism mediating the differential changes in fat pad mass seen in Siberian hamsters exposed to SDs. In conclusion, the present study provides the first direct anatomic evidence of innervation of TWAT and EWAT by the SNS in rodents. Moreover, these data support an important role for the SNS innervation of WAT that has been neglected traditionally.