Raeymaekers L, Agostini B, Hasselbach W
Histochemistry. 1980 Feb;65(2):121-9. doi: 10.1007/BF00493160.
A microsomal fraction was isolated from the smooth muscle of the antrum of the pig stomach by differential centrifugation. Electron microscopy of the negatively stained material showed that this fraction is heterogeneous in composition. The microsomes accumulated calcium in the presence of ATP, magnesium and oxalate. The amount of calcium taken up per mg protein was in the same range as observed for other smooth muscle microsomal preparations. Although this amount is much smaller than that in the microsomal fraction of skeletal muscle, calcium oxalate crystals were formed in some vesicles, as occurs in the skeletal muscle fragmented sarcoplasmic reticulum. Through the presence of the calcium oxalate crystals, many of these vesicles acquired sufficient mass and density to allow them to be isolated by centrifugation. A purification of about 40 fold in terms of calcium content was reached.
通过差速离心从猪胃窦平滑肌中分离出微粒体部分。对经负染的材料进行电子显微镜观察表明，该部分在组成上是异质的。微粒体在ATP、镁和草酸盐存在的情况下积累钙。每毫克蛋白质摄取的钙量与其他平滑肌微粒体制剂中观察到的量处于相同范围。尽管这个量比骨骼肌微粒体部分中的量小得多，但在一些囊泡中形成了草酸钙晶体，这与骨骼肌破碎的肌浆网中发生的情况一样。由于草酸钙晶体的存在，许多这些囊泡获得了足够的质量和密度，从而能够通过离心分离出来。就钙含量而言，达到了约40倍的纯化。
