Date of Award
Sulie L. Chang
Morphine, Permeability, Vascular Endothelial Cell Barriers
Using three types of in vitro endothelial cell barrier models, we investigated the direct effects and mechanisms of morphine on vascular permeability. Our current studies illustrate LPS induces permeability across these VEC barriers, and is significantly enhanced when co-treated with morphine, displayed using the [ 14 CJ-inulin paracellular marker. Incubation with morphine alone induces permeability in a concentration depeodent manner, and is not blocked by the addition of naloxone. Morphine enhances the detrimental effects of LPS on cell viability and alone also decreases endothelial cell viability, concentration-dependently, which is also not affected by naloxone, as demonstrated by the trypan blue exclusion assay. Using 4',6-diarnidino-2-phenylindole (DAPI) nuclear stain, we reveal LPS- and morphine-induced cell death is through an apoptotic mechanism. Morphine-induced apoptosis is concentration-dependent and not blocked by naloxone once again, and cotreatment with LPS synergizes to induce enhanced apoptosis. Morphine has been shown to induce Fas-mediated apoptosis in immune cells (Yin et al., 1999); however, our VEC models demonstrate a Fas independent apoptotic mechanism. Lastly, we confirm that pretreatment of the monolayer with morphine enhances viral penetration, using The Amplicor® Viral RNA Detection Assay. These results suggest that morphine enhances permeability and viral penetration across the vascular endothelium by promoting apoptosis, via a Fas independent pathway. This study reveals insight as to how morphine exposure may enhance HIV -1 penetration and further implicate the effects of endotoxins on these physiological barriers.
Anday, Jenine, "Morphine Enhances the Permeability Across Vascular Endothelial Cell Barriers" (2001). Seton Hall University Dissertations and Theses (ETDs). 2336.