GAP JUNCTIONS - STRUCTURAL-CHANGES AFTER UNCOUPLING PROCEDURES
GAP JUNCTIONS - STRUCTURAL-CHANGES AFTER UNCOUPLING PROCEDURES
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DOI：
10.1083/jcb.72.3.628
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发表时间：
1977-01-01
影响因子：
7.8
通讯作者：
PERACCHIA, C
中科院分区：
文献类型：
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作者：
PERACCHIA, C
高渗蔗糖抑制灌流代谢等去偶联过程后，大鼠胃和肝脏缝隙连接的冷冻断裂形态发生了变化。对照组立即固定胃，或在37度充氧的泰洛德S液中保存1h。粘液细胞间的缝隙连接多为不规则排列的颗粒，平均中心距为10.3~10.5 nm。在相同的温度和氧气条件下，用2，4-二硝基苯酚(DNP)处理1h后，大多数颗粒以平均间距为.apprx的六角形聚集。8.5 nm。在低氧的标本中也看到了类似的变化。在通过灌流固定的对照肝脏中，大多数连接颗粒以平均.apprx的中心到中心间距不规则地堆积。10 nm。偶尔可以看到规则的六角形堆积的小区域，平均粒子间距为9.2-9.5 nm。在低氧肝脏中，连接颗粒形成规则的六角形堆积，平均中心到中心的颗粒间距为8.5 nm。在EDTA溶液后再灌流高渗蔗糖-钙溶液的肝脏中，大多数连接被拉开。分离的连接膜，预计是高度不渗透的，含有规则和紧密堆积的颗粒，就像在低氧或DNP处理的连接处一样。初步测量表明，.apprx的颗粒直径可能发生了变化。8.6 nm(对照)至.apprx。7.7 nm(处理组)。这些结构变化与以前在小龙虾中报道的相似，可能反映了导致功能解偶联的粒子亚单位的构象变化。
The freeze-fracture appearance of rat stomach and liver gap junctions changed after uncoupling procedures such as inhibition of perfusion metabolism with hypertonic sucrose. In control stomach either fixed immediately or kept for 1 h in a well-oxygenated Tyrode''s solution at 37.degree. C, most gap junctions between mucous cells contained particles irregularly packed at an average center-to-center spacing of 10.3-10.5 nm. After 1-h treatment with 2,4-dinitrophenol (DNP) at the same temperature and oxygenation, most particles aggregated hexagonally at an average spacing of .apprx. 8.5 nm. Similar changes were seen in hypoxic specimens. In control liver fixed by perfusion, most junctional particles were irregularly packed at an average center-to-center spacing of .apprx. 10 nm. Small areas of fairly regular hexagonal packing were occasionally seen, where the average particle spacing was 9.2-9.5 nm. In hypoxic liver the junctional particles form regular hexagonal packings in which the average center-to-center particle spacing was 8.5 nm. In liver perfused with hypertonic sucrose-Ca solutions following EDTA solutions, most junctions were pulled apart. The separated junctional membranes, expected to be highly impermeable, contained particles regularly and tightly packed as in hypoxic or DNP-treated junctions. Preliminary measurements indicated a possible change in particle diameter from .apprx. 8.6 nm (control) to .apprx. 7.7 nm (treated). The structural changes were similar to those previously reported in crayfish and may reflect conformational changes in particle subunits resulting in functional uncoupling.