Dias V C, Yatscoff R W
Department of Laboratory Medicine and Pathology, Faculty of Medicine, University of Alberta, Edmonton, Canada.
Clin Biochem. 1994 Feb;27(1):31-6. doi: 10.1016/0009-9120(94)90008-6.
An in vitro intestinal cell culture model was used to characterize and investigate factors affecting uptake and transport of rapamycin (RAPA), a potent immunosuppressive drug. Studies were performed on three human intestinal cell monolayers (Caco-2, HCT-8, and T84), grown on microporous membrane inserts for 12 days. RAPA transport in all three monolayers was found to be dose dependent. The highest rates of transport were found at the highest tested final RAPA concentration of 10,000 micrograms/L. Apical to basal RAPA transport was linear in Caco-2 cell monolayers for up to 60 min, and in HCT-8 and T84 cell monolayers for up to 120 min. Temperature sensitive RAPA transport was found because incubation at 4 degrees C markedly attenuated transport by 97, 90, and 78% for Caco-2, HCT-8, and T84 monolayers, respectively. In all three monolayers RAPA transport was highly polarized because the apical to basal transport was greater than that in the opposite direction. RAPA uptake and transport across cell monolayers were compared when 10,000 micrograms/L of RAPA (cold) plus 0.05 microCi 14C-RAPA was added in combination with varying final concentrations (1,000, 10,000, and 100,000 micrograms/L) of the immunosuppressive drugs, CsA or RS. Increasing concentrations of CsA resulted in a significant dose-dependent decrease in 14C-RAPA transport across cell monolayers. In contrast, at high (100,000 micrograms/L) RS concentrations, 14C-RAPA transport was significantly increased. Uptake of 14C-RAPA into cell monolayers was significantly decreased only with the 100,000 micrograms/L CsA concentration. These studies suggest that combinations of immunosuppressive drugs given orally have a potential for altering the intestinal transport and uptake of RAPA.(ABSTRACT TRUNCATED AT 250 WORDS)
采用体外肠道细胞培养模型来表征和研究影响雷帕霉素（RAPA，一种强效免疫抑制药物）摄取和转运的因素。对在微孔膜插入物上生长12天的三种人肠道细胞单层（Caco - 2、HCT - 8和T84）进行了研究。发现所有三种单层中的RAPA转运均呈剂量依赖性。在最高测试终浓度10,000微克/升时发现了最高转运速率。在Caco - 2细胞单层中，顶侧到基底的RAPA转运在长达60分钟内呈线性，在HCT - 8和T84细胞单层中长达120分钟呈线性。发现RAPA转运对温度敏感，因为在4℃孵育时，Caco - 2、HCT - 8和T84单层的转运分别显著减弱97%、90%和78%。在所有三种单层中，RAPA转运高度极化，因为顶侧到基底的转运大于相反方向的转运。当加入10,000微克/升的RAPA（冷）加0.05微居里14C - RAPA并结合不同终浓度（1,000、10,000和100,000微克/升）的免疫抑制药物环孢素A（CsA）或雷帕霉素（RS）时，比较了RAPA跨细胞单层的摄取和转运。CsA浓度增加导致跨细胞单层的14C - RAPA转运显著呈剂量依赖性降低。相反，在高（100,000微克/升）RS浓度下，14C - RAPA转运显著增加。仅在100,000微克/升CsA浓度下，14C - RAPA进入细胞单层的摄取才显著降低。这些研究表明，口服免疫抑制药物组合有改变RAPA肠道转运和摄取的潜力。（摘要截断于250字）
