McGonigle P, Tallarida R J
Arch Int Pharmacodyn Ther. 1980 Nov;248(1):26-32.
The microsomal subcellular fraction was isolated from rabbit thoracic aorta by differential centrifugation between 3,000 g and 102,000 g. In one group of experiments, microsomes were incubated in the presence of angiotensin and the calcium binding was determined by liquid scintillation detection. In the other group, the incubation period with angiotensin included exposure to ultraviolet light for part of the time. Microsomes incubated with 10(-6) M angiotensin for 30 min demonstrated a 38% decrease in calcium binding below control level. When incubation with this same concentration of angiotensin was followed by a 20 min exposure to ultraviolet light (3660 A), the calcium binding increased 10% above control level. Irradiation in the absence of angiotensin for 20 min produced a 20% increase in calcium binding above control. Microsomes depleted of their endogenous catecholamine stores and not treated with any stimulating drug exhibited a 32% increase in calcium binding after irradiation with ultraviolet light. The effect of ultraviolet light on calcium binding was found to be positively correlated with the duration of irradiation. The enhanced microsomal binding of calcium due to ultraviolet light corresponds to the decrease in tension which this radiation produces in actively contracted aortic strips.
通过在3000g至102000g之间进行差速离心从兔胸主动脉中分离出微粒体亚细胞组分。在一组实验中，微粒体在血管紧张素存在的情况下孵育，并通过液体闪烁检测法测定钙结合情况。在另一组实验中，与血管紧张素一起孵育的时间段包括部分时间暴露于紫外线下。用10(-6)M血管紧张素孵育30分钟的微粒体显示钙结合比对照水平降低了38%。当用相同浓度的血管紧张素孵育后再暴露于紫外线（3660埃）20分钟时，钙结合比对照水平增加了10%。在无血管紧张素的情况下照射20分钟使钙结合比对照增加了20%。耗尽其内源性儿茶酚胺储备且未用任何刺激药物处理的微粒体在紫外线照射后钙结合增加了32%。发现紫外线对钙结合的影响与照射持续时间呈正相关。紫外线导致的微粒体钙结合增强与该辐射在主动收缩的主动脉条带中产生的张力降低相对应。
