Nickerson P A, Yang F
Department of Pathology, State University of New York, Buffalo 14214.
J Submicrosc Cytol Pathol. 1988 Apr;20(2):317-24.
The effect of deoxycorticosterone (DOC)-induced hypertension on the calcium content within the aorta was studied before the increase in pressure (one week) and after the pressure had reached hypertensive levels (4 weeks). The volume density of free calcium detected ultrastructurally by pyroantimonate precipitation was quantitated by stereological techniques in aortic smooth muscle cells. An increase in the volume density of electron opaque precipitate was observed in the cytoplasm at one week of DOC treatment when neither the systolic blood pressure, the thickness of the media nor volume fraction of medial smooth muscle as compared to the extracellular space was increased significantly. The total aortic calcium as measured by atomic absorption spectroscopy was not increased at one week. By 4 weeks when the rats were hypertensive, the cytoplasmic free calcium in the smooth muscle cells and the number of peripherally-located cytoplasmic vesicles with precipitate was increased significantly. Total aortic calcium was also increased significantly in the DOC-saline group but not in the DOC group drinking tap water or in the saline drinking controls. An elevation of calcium within the cytoplasm of vascular smooth muscle cells may precede the development of hypertension and play a role in the pathogenesis of the increased blood pressure, increased medial thickness and hypertrophy of the vascular smooth muscle cells.
研究了脱氧皮质酮（DOC）诱导的高血压对主动脉内钙含量的影响，分别在血压升高前（一周）和血压达到高血压水平后（四周）进行观察。采用焦锑酸盐沉淀法超微结构检测游离钙的体密度，并通过体视学技术对主动脉平滑肌细胞中的游离钙进行定量分析。在DOC治疗一周时，尽管收缩压、中膜厚度以及中膜平滑肌与细胞外空间的体积分数均未显著增加，但在细胞质中观察到电子不透明沉淀物的体密度增加。通过原子吸收光谱法测定，一周时主动脉总钙含量未增加。到四周时大鼠出现高血压，平滑肌细胞中的细胞质游离钙以及周边带有沉淀物的细胞质囊泡数量显著增加。在DOC-生理盐水组中，主动脉总钙含量也显著增加，但在饮用自来水的DOC组或饮用生理盐水的对照组中未出现这种情况。血管平滑肌细胞质内钙升高可能先于高血压的发生，并在血压升高、中膜厚度增加以及血管平滑肌细胞肥大的发病机制中起作用。
