【摘要】 本文是试制一种适合于临床应用的胆固醇示踪物。研制成的I-6-碘代胆固醇在结晶形状,成色反应、沉淀反应及红外线吸收光谱等方面都和胆固醇很相似,且有很高的化学与生物稳定性。此标记物与胆固醇,同时给予家兔或大鼠后,在动物肝、血浆及血管壁动脉粥样硬化斑块中浓度的变化彼此平行。目前它巳用于临床,作为肾上腺显影剂。更多还原

【Abstract】 Cholesterol has been labeled with radioiodine by two methods: ( 1 ) mercura-tion of cholesterol and subsequent replacement of the chloromercuri group with 131I2;( 2) exchange of 6-iodo-cholesterol with radioactive iodide in aqueous butanolsolution. The radiochemical purity of the final product was demonstrated by paperchromatography and autoradiography.It was found that iodine was firmly bound in the iodinated cholesterol molecule. No appreciable loss of the label was observed and the original compound was recovered unchanged after refluxing for 3 hours the radioiodinated cholesterol in butanol solution containing either concentrated sodium ethoxide or hydrogen chloride.The labeled cholesterol resembles cholesterol itself in many respects. It crystallizes in pearly leaflets. It is precipitated by digitonin and gives intense red color with Zak’s reagent. Its infrared absorption spectrum practically coincides with that of cholesterol in all of the main absorption bands.Above all, "the most interesting property of the radioiodinated cholesterol lies in its behavior in animal experiments. After being given intravenously to rabbits or rats together with unlabeled cholesterol, the labeled cholesterol appeared in plasma, liver and atherosclerotic plaques of the animal in such a manner that the changes in concentration of the two administered compounds closely paralleled to ,each other.Since the radioative isotope 131I is a cheap γ-emitter with relatively short half-life and its amount within the body can be easily measured from outside, this radioiodinated cholesterol might be useful as a diagnostic aid in clinical conditions involving cholesterol disturbance. As a matter of fact, it has already been used successfully in several Chinese hospitals as an imaging agent for adrenal visualization.更多还原