Engel J, Ermakov Y A, Richter W, Donath E
Department of Biology, Humboldt University, Berlin, G.D.R.
Biochim Biophys Acta. 1990 Oct 19;1028(3):236-44. doi: 10.1016/0005-2736(90)90172-k.
When bovine chromaffin granules are incubated in hyperosmolar sucrose solutions and subsequently transferred back towards isoosmolarity they undergo lysis ('hyperosmotic relaxation lysis'). This type of lysis was compared with the common effect of hypotonic lysis by means of photon correlation spectroscopy (PCS) and freeze-fracture electron microscopy. Both methods revealed differences regarding mean sizes and size distributions of granules lysing under either hypotonic or hypertonic conditions. However, the results obtained by these two methods were not consistent. In the case of hypotonic lysis, a nonmonotonic behaviour of the mean diameter as a function of the sucrose concentration was observed by PCS, but not in the micrographs. From EM size determinations we obtained a decrease in the mean diameter and an increase of the width of the distribution due to the appearance of small (50-200 nm) vesicles. Probably these vesicles are intragranular vesicles released during lysis. The maximum in photon correlation spectroscopy (PCS) diameter being 140% of the isotonic diameter is shown to be caused by the changing size distribution and geometry of the lysing granules. In the case of hyperosmotic relaxation, micrographs revealed that originally shrunken, nonspherical granules regained their spherical shape and formed small (60 nm) vesicles upon lysis. In contrast, no difference was observed between the sizes of granules prior to and after hyperosmotic relaxation by means of PCS. The paper discusses the validity of intensity-weighted light scattering data of polydisperse particle suspensions with changing size distributions. The mechanism of hyperosmotic relaxation lysis is considered.
当牛嗜铬颗粒在高渗蔗糖溶液中孵育，随后转移回等渗状态时，它们会发生裂解（“高渗松弛裂解”）。通过光子相关光谱法（PCS）和冷冻断裂电子显微镜，将这种裂解类型与低渗裂解的常见效应进行了比较。两种方法都揭示了在低渗或高渗条件下裂解的颗粒在平均大小和大小分布方面的差异。然而，这两种方法得到的结果并不一致。在低渗裂解的情况下，PCS观察到平均直径随蔗糖浓度的变化呈现非单调行为，但在显微照片中未观察到。通过电子显微镜尺寸测定，我们发现由于小泡（50 - 200纳米）的出现，平均直径减小，分布宽度增加。这些小泡可能是裂解过程中释放的颗粒内小泡。光子相关光谱法（PCS）直径的最大值为等渗直径的140%，这表明是由裂解颗粒不断变化的大小分布和几何形状导致的。在高渗松弛的情况下，显微照片显示，最初收缩的非球形颗粒恢复了球形，并在裂解时形成了小泡（60纳米）。相比之下，通过PCS未观察到高渗松弛前后颗粒大小的差异。本文讨论了大小分布不断变化的多分散颗粒悬浮液强度加权光散射数据的有效性。文中还考虑了高渗松弛裂解的机制。
