WATER DISTRIB:PHYSICAL PROPERT:PIZZA & LMPS MOZZARELLA CHEESES:EARLY STAGE MATUR

这些研究是使用离体犬脑进行的 用具有正常pH、PaO 2、PaCO 2、葡萄糖的血液灌注， 温度和采用高场（9.4特斯拉），宽孔（89 mm） 磁体（Bruker Instruments AM-400 WB）用于NMR研究。 该地区 与Pi相关的31 P光谱的非线性 曲线拟合（Peak-Fitr，Jandel Scientific）以去卷积峰。 我们已经证明，宽无机磷酸盐（Pi）峰与 4.00至5.25 ppm的化学位移可以一致地分解为 五到七个独立的峰 将Pi缓冲液调节至pH 7.40， 在15分钟内输注以提高血液Pi浓度 这导致与pH为2至4 mM的区室相关的峰。 7.35（血浆）和pH 7.18（间质液）的体积增加。 我们还在30分钟内输注40 mg 2-脱氧葡萄糖（2-DG） 期间，并继续收集数据额外的30分钟 输注后。 脑细胞中2-DG的磷酸化 导致2-DG-6-P在磷酸单酯（PME）中积累 光谱的一部分。 2-DG-6-P峰在pH值下， 对应于Pi谱中的三个峰， 由于高能磷酸盐水解， 缺血（pH 7.05、6.95和6.82）。 根据部分证据， 我们相信这些峰值代表了 星形胶质细胞神经元可能还有少突胶质细胞 这些研究 这表明，通常可能只有三个细胞质和两个 脑组织Pi谱中的细胞外区室， 在2-DG输注期间，Pi峰福尔斯下降。 通过 从对照中减去2-DG输注期间的Pi谱 光谱和拟合的差异，我们发现，Pi消失， 出现2-DG-6-P的相同pH隔室。 高血糖 在缺血期间导致pHi比在缺血期间显著进一步下降， 血糖正常的缺血 令人惊讶的是，高血糖的大脑 10分钟后保持一些高能磷酸盐 缺血

These studies were conducted using the isolated canine brain perfused with blood having a normal pH, PaO2, PaCO2, glucose, and temperature and employing a high field (9.4 Tesla), wide bore (89 mm) magnet (Bruker Instruments AM-400 WB) for the NMR studies. The region of the 31P spectrum associated with Pi was subjected to nonlinear curve fitting (Peak-Fitr, Jandel Scientific) to deconvolute the peaks. We have demonstrated that the broad inorganic phosphate (Pi) peak with a chemical shift of 4.00 to 5.25 ppm can be consistently resolved into five to seven separate peaks. A Pi buffer adjusted to pH 7.40 was infused over a 15 minute period to raise the blood Pi concentration from 2 to 4 mM. This caused peaks associated with compartments at pH 7.35 (plasma) and pH 7.18 (interstitial fluid) to increase in size. We also infused 40 mg of 2-deoxyglucose (2-DG) over a 30 minute period, and continued to collect data for an additional 30 minutes following infusion. Phosphorylation of 2-DG in the brain cells resulted in 2-DG-6-P accumulation in the phosphate monoester (PME) portion of the spectrum. The 2-DG-6-P peaks were at pHs which corresponded to the three peaks in the Pi spectrum which increased dramatically in size due to high energy phosphate hydrolysis during ischemia (pH 7.05, 6.95, and 6.82). Based on partial evidence from this and other studies, we believe these peaks represent the astrocyte, neuron, and possibly the oligodendrocyte. These studies suggested that there may normally be only three cytoplasmic and two extracellular compartments in the brain tissue Pi spectrum that are defined by pH. The Pi peak falls during 2-DG infusion. By subtracting the Pi spectrum during the 2-DG infusion from the control spectrum and fitting the difference, we find that Pi disappears from the same pH compartments in which 2-DG-6-P appears. Hyperglycemia during ischemia causes pHi to fall significantly further than during normoglycemic ischemia. Surprisingly, the hyperglycemic brains maintain some high energy phosphate after 10 minutes of complete ischemia.