Touchstone Center for Diabetes Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
Int J Obes (Lond). 2010 Feb;34(2):396-400. doi: 10.1038/ijo.2009.245. Epub 2009 Dec 15.
The aim of this study was to determine if the fat accumulation in the exocrine pancreas fat of obese Zucker diabetic fatty (ZDF) rodents, like that in their endocrine pancreas, precedes the onset of type 2 diabetes mellitus (T2DM). As the fat content of whole pancreas, but not islets, can now be measured in humans by magnetic resonance spectroscopy (MRS), such measurements could be used as a predictor of impending T2DM and an indication for preventive intervention.
Obese ZDF (fa/fa) rats and lean (+/+) controls on a 6% fat diet were killed at time points from 6 to 16 weeks and total pancreatic fat was measured biochemically and electronmicroscopic examination of tissue for fat droplets was carried out.
Compared to lean ZDF controls, pancreatic fat was elevated above lean controls from 6 to 16 weeks of age, peaking at 10 weeks of age when hyperglycemia first appeared. The pancreatic profile of fat content in whole pancreas paralleled that of islets. Electronmicroscopic examination identified the acinar location of the fat droplets and ruled out a major contribution of intrapancreatic adipocytes.
The almost identical pattern of triglyceride overaccumulation in the exocrine and endocrine pancreas of obese rodents before the onset of T2DM suggests that MRS of the human pancreas might predict T2DM in obese subjects and permit timely interventions to prevent the disease.
本研究旨在确定肥胖型 Zucker 糖尿病肥胖(ZDF)鼠的外分泌胰腺脂肪中的脂肪堆积是否像其内分泌胰腺那样,先于 2 型糖尿病(T2DM)的发生。由于磁共振波谱(MRS)现在可以测量人体整个胰腺而不仅仅是胰岛的脂肪含量,因此这些测量值可以用作即将发生 T2DM 的预测指标,并提示需要进行预防性干预。
肥胖型 ZDF(fa/fa)大鼠和低脂(+/+)对照大鼠在 6%脂肪饮食下,从 6 周到 16 周处死,通过生化方法测量总胰腺脂肪,并进行组织脂肪滴的电子显微镜检查。
与低脂 ZDF 对照组相比,从 6 周到 16 周,胰腺脂肪高于低脂对照组,在首次出现高血糖的 10 周时达到峰值。整个胰腺脂肪含量的胰腺特征与胰岛相似。电子显微镜检查确定了脂肪滴在腺泡中的位置,并排除了胰腺内脂肪细胞的主要贡献。
在 T2DM 发生之前,肥胖型啮齿动物的外分泌和内分泌胰腺中甘油三酯过度积累的几乎相同模式表明,人类胰腺的 MRS 可能预测肥胖人群中的 T2DM,并允许及时进行干预以预防该疾病。