PubMed · 15880156
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Olav Spigset, Lars Slørdal. 2005-05-04. [Basic pharmacokinetics--elimination].. https://pubmed.ncbi.nlm.nih.gov/15880156/
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PURPOSE: To evaluate the effect of bile on growth and proliferation of human umbilical vein endothelium cultured in vitro, with a view toward clarifying the effect of bile leakage during transjugular intrahepatic portosystemic shunt creation. MATERIALS AND METHODS: This study was approved by the ethical review committee, and written informed consent was obtained from all mothers. Endothelial cells (ECs) were collected from human umbilical veins and cultured in vitro. After 24-48 hours in culture, ECs were distributed into groups supplemented with the following concentrations of bile in the culture medium: 0%, 5.0%, 10.0%, 15.0%, 20.0%, and 25.0%. The cells were harvested 5 days after supplementation with bile. The morphologic features, von Willebrand factor (vWF) level, tetrazolium salt (MTT) assay value of light absorption, total protein level, and nitric oxide synthase (NOS) activity of the ECs were evaluated. RESULTS: All explanted cells were identified as ECs by using the vWF test. Compared with ECs in the control group without bile, ECs in culture medium with a bile concentration of 5.0%, 10.0%, or 15.0% showed no marked morphologic changes, whereas ECs in culture medium with a bile concentration of 20.0% or 25.0% were reduced greatly in number and looked markedly immature. The MTT value of light absorption, total protein level, and vWF secretion were significantly decreased (P < .05 for all) in ECs in culture medium with 25.0% bile compared with these parameters in ECs in culture medium without bile, although these parameters did not significantly differ between the ECs in culture medium of 5.0% or 10.0% bile and the ECs in culture medium without bile. Compared with NOS activity in ECs when no bile was present in the culture medium, NOS activity in ECs was significantly decreased at all bile concentrations (P < .05). CONCLUSION: Low concentrations of bile do not markedly inhibit cell growth; the inhibiting effect of bile on ECs progresses with an increase in bile concentration.
Cholesterol crystals are the building blocks of cholesterol gallstones. The exact structure of early-forming crystals is still controversial. We combined cryogenic-temperature transmission electron microscopy with cryogenic-temperature electron diffraction to sequentially study crystal development and structure in nucleating model and native gallbladder biles. The growth and long-term stability of classic cholesterol monohydrate (ChM) crystals in native and model biles was determined. In solutions of model bile with low phospholipid-to-cholesterol ratio, electron diffraction provided direct proof of a novel transient polymorph that had an elongated habit and unit cell parameters differing from those of classic triclinic ChM. This crystal is exactly the monoclinic ChM phase described by Solomonov and coworkers (Biophysical J., In press) in cholesterol monolayers compressed on the air-water interface. We observed no evidence of anhydrous cholesterol crystallization in any of the biles studied. In conclusion, classic ChM is the predominant and stable form in native and model biles. However, under certain (low phospholipid) conditions, transient intermediate polymorphs may form. These findings, documenting single-crystal analysis in bulk solution, provide an experimental approach to investigating factors influencing biliary cholesterol crystal nucleation and growth as well as other processes of nucleation and crystallization in liquid systems.
UNLABELLED: Cholesterol crystallization is a prerequisite for gallstone formation and growth, whereas dissolution of crystallized cholesterol forms the basis of nonsurgical therapy. Crystallization has been studied in detail, but dissolution mechanisms and effects of gallstones are largely unknown. METHODS: We evaluated gallstone growth or dissolution, cholesterol crystallization and lipid distribution into various phases, in model biles with low or intermediate phospholipid contents (crystal-containing left two-phase or central three-phase zones), and with high phospholipid or low cholesterol contents (crystal-free right two-phase or bottom one-phase zones). RESULTS: In model biles with added gallstones plotting in left two-phase and central three-phase zones, gallstone masses increased, whereas crystallization in the aqueous phase was less than without gallstones (P<0.001). In biles plotting in the right two-phase zone, gallstone masses decreased, depending on bile salt hydrophobicity (TUDC>TC>TCDC: P<0.001). In biles plotting in the bottom one-phase zone containing TC or TCDC, gallstone masses increased. In contrast, gallstone masses decreased in case of TUDC with preferential distribution of cholesterol into emerging vesicles. CONCLUSIONS: Our findings suggest competition between gallstone surface and surrounding aqueous phase for precipitation of cholesterol in crystal-containing zones. Different gallstone dissolution mechanisms may exist for TUDC and TCDC.