Wadsworth R M, Berezin I, Crankshaw J, Kwan C Y, Daniel E E
Smooth Muscle Research Program, McMaster University Health Sciences Centre, Hamilton, Ont., Canada.
Blood Vessels. 1988;25(4):166-84. doi: 10.1159/000158730.
Collagenase and elastase treatment was used to isolate vascular smooth muscle cells from canine carotid artery. Their structure and function were compared to those in situ. Morphological studies showed that these cells when relaxed in situ were 120-133 micron mean length, connected by numerous typical gap junctions, covered by a basal lamina and like other smooth muscles in structure. After isolation, the median length of single cells was 82 micron. There was structural evidence of some contraction and the basal lamina was absent, but many structures were preserved. Cell clumps of 2-15 cells were often found; cells in such clumps often appeared to be all relaxed or all contracted. Isolated single cells contracted to KCl elevation or to norepinephrine up to 49 or 37% of initial length, EC50 values for contraction by norepinephrine and KCl were 0.4 microM and 40 mM, respectively; norepinephrine maximum contraction was about 35% less than that for KCl. Lightly loaded spirally cut strips from carotid artery were also studied. EC50 values for norepinephrine and KCl were 4 microM and 40 mM and unaffected by removal of the endothelium. Again, maximum contractions to norepinephrine were less than those to KCl. Contraction speeds were similar for isolated cells and intact strips. However, relaxation of maximally contracted isolated cells did not occur within 10 min. We conclude that canine carotid artery smooth muscle cells can be isolated with little structural or functional damage. The large number of gap junctions between cells and the tendency for cells to be isolated in small groups connected by gap junctions suggests that these cells would be useful for study of cell-to-cell coupling between arterial muscle cells.
采用胶原酶和弹性蛋白酶处理从犬颈动脉中分离血管平滑肌细胞。将其结构和功能与原位细胞进行比较。形态学研究表明，这些细胞在原位舒张时平均长度为120 - 133微米，通过众多典型的缝隙连接相连，被基膜覆盖，结构上与其他平滑肌相似。分离后，单个细胞的中位长度为82微米。有结构证据表明存在一些收缩，且基膜缺失，但许多结构得以保留。经常发现由2 - 15个细胞组成的细胞团；此类细胞团中的细胞通常似乎全部舒张或全部收缩。分离的单个细胞对氯化钾升高或去甲肾上腺素的收缩可达初始长度的49%或37%，去甲肾上腺素和氯化钾收缩的EC50值分别为0.4微摩尔/升和40毫摩尔/升；去甲肾上腺素的最大收缩比氯化钾约少35%。还研究了颈动脉轻度加载的螺旋切片条。去甲肾上腺素和氯化钾的EC50值分别为4微摩尔/升和40毫摩尔/升，且不受内皮去除的影响。同样，去甲肾上腺素的最大收缩小于氯化钾。分离细胞和完整切片条的收缩速度相似。然而，最大收缩的分离细胞在10分钟内未发生舒张。我们得出结论，犬颈动脉平滑肌细胞可以在结构或功能几乎无损伤的情况下被分离。细胞间大量的缝隙连接以及细胞倾向于以通过缝隙连接相连的小群体形式被分离，表明这些细胞将有助于研究动脉肌细胞之间的细胞间偶联。
