Dexamethasone palmitate

Dexamethasone palmitate results in decrease in transmonolayer paracellular permeability mainly to sucrose, fluorescein and dextrans of up to 20 KDa in an immortalised rat brain endothelial cell line (GPNT). This compound results in filamentous actin and the cytoskeleton associated protein cortactin being highly concentrated in the regions of cell-cell contact with few F-actin stress fibres visible within the cytoplasm in cultured rat brain endothelial cells, an observation consistent with a more differentiated barrier phenotype induced by this chemical. This compound treatment has been shown to strongly stimulate the level of the Id-1 protein, which is a serum-inducible helix-loop-helix transcriptional repressor, involved in cell differentiation, and this effect was shown to be associated with reorganisation of ZO-1 to the cell periphery in Con8 mammary epithelial tumor cells. This chemical prevents cytokine-induced enhanced expression of MMP-9 and alterations in the expression of ZO-1 in untreated GPNT monolayers. [1] It depletes both basal and TNF-alpha-stimulated GSH levels by down-regulating the gamma-GCS-heavy subunit transcription via a mechanism involving AP-1 (c-Jun) in alveolar epithelial cells. This compound decreases both basal and stimulated GSH levels (TNF-α-treated) in alveolar epithelial cells (A549), without any change in GSSG. [2]

Dexamethasone palmitate is administered i.m. to pregnant ewes, leads to the following results (1) blood pressure is unchanged; (2) as previously reported in the fetus, sensitivity to endothelin-1 (ET) is increased; (3) acetylcholine-induced relaxation is increased; (4) L-NAME suppressible vasodilatory response to ET is abolished; (5) there is no change in endothelium-independent vasodilatation; and (6) there is no change in eNOS RNA and protein levels, when compared to saline treated controls. [3]