Regulatory mechanisms of cytosolic ion transients during cell cycle progression in vascular endothelial and smooth muscle cells

1.血管平滑肌细胞增殖及其与细胞功能的关系我建立了原代培养的同一单个细胞的细胞周期时相和细胞功能的测定方法。结果发现：(1)钙通道类型的表达随细胞周期的变化而变化；(2)P2u受体的激活刺激细胞周期从G1期进入S/M期，而不是从G0期进入G1期，而使G0期和C1期的细胞内钙离子浓度([Ca^&lt；2&gt；]i)均升高；(3)钙通道阻滞剂对钙离子浓度的影响不同。结论：1.血管平滑肌细胞的瞬变与细胞周期进程。(1)阐明了血管扩张剂对血管收缩的不同作用机制([Ca^&lt；2&gt；]i-force关系、[Ca^&lt；2&gt；2&gt；收缩装置敏感性和mRNA表达]。(2)静息负荷调节血管平滑肌收缩的[Ca~(2+)]-力关系。(3)Rho-Kinase可诱导肌球蛋白轻链磷酸化和非钙依赖性收缩，该作用不依赖于钙调素-MLCK途径。(4)缓激肽可通过激活B_2受体和G蛋白，增加收缩装置的[Ca~(2+)]i和Ca~(2+)~(lt；2&gt)敏感性。(5)酪氨酸激酶抑制剂对猪冠状动脉病变有明显的抑制作用。(6)移植到动脉循环中的自体大隐静脉的内毒素B受体表达下调。(7)提示内皮素可能是调节气道平滑肌收缩的自分泌和/或旁分泌递质。

The following results were obtained :1. CELL PROLIFERATION OF VASCULAR SMOOTH MUSCLE CELLS AND ITS RELATION TO THE CELLULAR FUNCTION.I developed the method to determine both the phase of the cell cycIe and cell function of the same single-cell of vascular smooth muscle cells (VSMCs) in primary culture. It was found that : (1) the expression of types of Ca^<2+> channels changes with the cell cycle ; (2) the activation of P2u receptor stimulates the cell cycle progression from the G1 to the S/M phases, but not from the G0 to G1 phase, whereas it elevates cytosolic Ca^<2+> concentration ([Ca^<2+>] i) in the VSMCs at the G0 and C1 phases equally ; and (3) Ca^<2+> channel blockers differently affect Ca^<2+> transients and cell cycle progression in VSMCs.2. VASCULAR CONTRACTION.(1) Differential mechanisms ([Ca^<2+>]i-force relation, Ca^<2+> sensitivity of contractile apparatus, and mRNA expression) of vasorelaxation by vasodilators were elucidated. (2) It was found that resting load regulates [Ca^<2+>] i-force relation of the contraction of vascular smooth muscle. (3) It was found that Rho-kinase induces myosin light chain phosphorylation and Ca^<2+>-independent contraction, which is independent of the Ca^<2+>- calmodulin-MLCK pathway. (4) Bradykinin was shown to elevate [Ca^<2+>] i and Ca^<2+> sensitivity of contractile apparatus, as mediated by the activation of the B2 receptor and G-proteins. (5) It was demonstrated that tyrosine kinase Inhibitor markedly suppressed the development of coronary lesions in pig in vivo. (6) Down-regulation of endotihelin B receptors was observed in autogenous saphenous veins grafted into the arterial circulation. (7) It was suggested that endothelins may be autocrine and/or paracrine transmitters 'to regulate the contraction of airway smooth muscle.