Watts S W, Tsai M L, Loch-Caruso R, Webb R C
Department of Physiology, University of Michigan Medical School, Ann Arbor.
J Vasc Res. 1994 Nov-Dec;31(6):307-13. doi: 10.1159/000159057.
Oscillatory contractions in uterine smooth muscle are mechanistically related to gap junction complex formation. We have tested the hypothesis that agonist-induced oscillations in vascular smooth muscle are also mediated by gap junctions and that gap junctions are important for vascular smooth muscle cell communication. Total RNA from cultured Wistar-Kyoto rat (WKY) mesenteric arterial cells hybridized strongly with a cDNA probe for the message for connexin43, a monomer of the gap junction. In these same cells, the quaternary ion tetraethylammonium (TEA) (10 mM) increased Lucifer yellow dye transfer between contiguous cells, a measure of cell-to-cell communication via gap junctions, approximately 35% above basal levels. Heptanol, an established inhibitor of gap junction communication, completely blocked both basal- and TEA-stimulated dye transfer between neighboring cells. In other experiments, helical strips of superior mesenteric and tail arteries from WKY rats were mounted in tissue baths for measurement of isometric contractile force. TEA (10(-3)-10(-1) M) induced oscillatory contractions (1-5 cycle/min) in both mesenteric and tail arteries. Removal of endothelium did not affect the pattern of TEA-stimulated oscillations. Oscillations to TEA were blocked in a concentration-dependent manner in both arteries by heptanol (10(-7)-10(-3) M). Heptanol (10(-3) M) also significantly reduced (40%) acetylcholine-induced relaxation in the mesenteric artery (contracted with phenylephrine).(ABSTRACT TRUNCATED AT 250 WORDS)
子宫平滑肌的振荡性收缩在机制上与缝隙连接复合体的形成有关。我们检验了这样一个假说，即激动剂诱导的血管平滑肌振荡也由缝隙连接介导，且缝隙连接对血管平滑肌细胞通讯很重要。来自培养的Wistar-Kyoto大鼠（WKY）肠系膜动脉细胞的总RNA与缝隙连接单体连接蛋白43的cDNA探针强烈杂交。在这些相同的细胞中，季铵离子四乙铵（TEA）（10 mM）使相邻细胞间的荧光黄染料转移增加，这是通过缝隙连接进行细胞间通讯的一种测量方法，比基础水平高出约35%。庚醇是一种已确定的缝隙连接通讯抑制剂，它完全阻断了相邻细胞间基础和TEA刺激的染料转移。在其他实验中，将WKY大鼠肠系膜上动脉和尾动脉的螺旋条安装在组织浴中以测量等长收缩力。TEA（浓度为10⁻³ - 10⁻¹ M）在肠系膜动脉和尾动脉中均诱导出振荡性收缩（1 - 5次/分钟）。去除内皮并不影响TEA刺激的振荡模式。在两条动脉中，庚醇（10⁻⁷ - 10⁻³ M）以浓度依赖的方式阻断了对TEA的振荡。庚醇（10⁻³ M）也显著降低了（40%）乙酰胆碱诱导的肠系膜动脉舒张（用去氧肾上腺素预收缩）。（摘要截短于250字）
