Spady D K, Meddings J B, Dietschy J M
J Clin Invest. 1986 May;77(5):1474-81. doi: 10.1172/JCI112460.
In this study, carried out in the rat and hamster, the receptor-dependent low density lipoprotein (LDL) transport process in each organ was characterized in terms of its maximal uptake rate (Jm) and Michaelis constant (Km), while the rate of receptor-independent uptake was defined in terms of its proportionality constant (P). The highest Jm values of 50-126 micrograms/h per g were found in the liver and endocrine glands in both species and receptor-dependent uptake also was detected in other organs like spleen, kidney, and intestine. The Km values were essentially the same in all of the organs and equaled approximately 90 mg/dl in both species. The receptor-independent uptake constants also were similar in the two species and were highest in the spleen, liver, and intestine. From these values for Jm, Km, and P, it was possible to construct theoretical curves that predict the plasma LDL-cholesterol concentration and fractional catabolic rate given any alteration in LDL-cholesterol production or the magnitude of receptor-dependent LDL transport in any organ of the rat or hamster.
在这项以大鼠和仓鼠为实验对象的研究中，各器官中受体依赖性低密度脂蛋白（LDL）转运过程的特征表现为其最大摄取率（Jm）和米氏常数（Km），而受体非依赖性摄取率则依据其比例常数（P）来定义。在这两个物种中，肝脏和内分泌腺的Jm值最高，为每克每小时50 - 126微克，并且在脾脏、肾脏和肠道等其他器官中也检测到了受体依赖性摄取。所有器官中的Km值基本相同，在这两个物种中均约为90毫克/分升。受体非依赖性摄取常数在这两个物种中也相似，在脾脏、肝脏和肠道中最高。根据这些Jm、Km和P值，可以构建理论曲线，以预测在大鼠或仓鼠的任何器官中，LDL - 胆固醇生成发生任何变化或受体依赖性LDL转运量发生任何改变时的血浆LDL - 胆固醇浓度和分数分解代谢率。
