长期高脂饮食对大鼠下丘脑腹内侧核、弓状核PGC-1α表达的影响

The distribution and significance of PGC-1α neurons in the centre of energy homeostasis in hypothalamus

目的观察高脂饮食对下丘脑腹内侧核、弓状核PGC-1α表达的影响。方法 SD大鼠随机分为正常饮食组及高脂饮食组,喂养8周后,采用HE染色法观察肝脏组织脂肪变性情况,采用免疫荧光化学法染色,观察PGC-1α在下丘脑腹内侧核、弓状核的表达变化。结果 8周后正常饮食组大鼠肝组织的肝索排列整齐,肝索、肝血窦、肝细胞之间均界限分明,细胞核清晰,胞浆均匀,未见肝细胞脂变和坏死;而摄取高脂饮食的大鼠的肝脏组织表现为肝索排列紊乱、肝血窦腔隙极小、细胞界限不清、肝细胞肿胀,胞浆中出现了大小不等的脂肪空泡,有严重脂肪变性特征。正常饮食大鼠下丘脑腹内侧核测定区域面积下PGC-1α的细胞数为199.96±42.95,高脂饮食大鼠腹内侧核PGC-1α的细胞数为(256.08±39.25),二者具有统计差异P<0.05;正常饮食大鼠弓状核PGC-1α的细胞数为(173.25±47.19),高脂饮食大鼠弓状核PGC-1α的细胞数为(200.48±51.44),二者具有统计差异P<0.05。结论高脂饮食导致下丘脑腹内侧核、弓状核PGC-1α表达增高,可能与能量代谢平衡调节功能有关。

Objective To investigate the role of high fat diet in the distribution of PGC-1αin SD rat hypothalamus. Methods 12 SD rats were randomly divided two groups, a normal diet group and a high fat diet group. HE staining was used to detect the fatty degeneration of the liver tissue; Immunofluorescence staining was used to observe the change of PGC-1α in the hypothalamusventromedial nucleus, and arcuate nucleus after 8 weeks. Results 8 weeks later, the live tissue of normal diet rats showed that hepatic cord was well organized;the boundary among hepatic cord, liver blood sinus and liver cells was clear;the nucleus were clear and cytoplasmhomogeneous;there was no liver cell lipid and necrosis. But the high fat diet rat live tissues expressed the characteristic of serious fatty degeneration, such as hepatic corddisorganized, liver blood sinus cavity became smaller, the boundary was not clear, live cells swelling with fat vacuoles in the cytoplasm which was not uniform in size. The PGC-1α cell number in the normal diet rat hypothalamusventromedial nucleus determination area was （199.96 ± 42.95）, but it was （256.08 ± 39.25） in the high fat diet rat, and there was statistical significance（P〈0.05）. In the arcuate nucleus the cell number of PGC-1αwas （173.25±47.19） in the normal diet rat, but high fat diet made the cell number increased to 200.48±51.44, and there was statistical significance between them（ P〈0.05）. Conclusion High fat diet made the cell number of PGC-1αincreased in ventromedial nucleus andarcuate nucleus, PGC-1α may play a role in regulating the energy metabolism balance.