Dexamethasone

In murine macrophages serotonin antagonists (250 (iM methysergide, cyproheptadine or spiperone) inhibited the binding of serotonin and muramyl peptides and the respiratory burst induced by these stimuli (Silverman et al. 1985). These data suggest that muramyl peptides and serotonin act via the same receptor. 

During the respiratory burst of human blood monocytes serotonin acts as a radical scavenger and is oxidised to a dimer, probably 5,5 -dihydroxy-4,4 -bitryptamine (Schuff-Werner et al. 1995). 

Treatment of RAW 264.7 cells with dexametha-sone reduced the formation of nitrite, one of the stable end products of NO production as measured in culture supernatants (Walker et al. 1997). The IC50 is approximately 9 nM of dexamethasone. The reduction of iNOS activity is caused by decreased iNOS protein levels as assessed by immunoblotting using a specific anti-iNOS-antibody. Dexamethasone treatment reduces the formation of iNOS mRNA steady state levels by about 50 % of IFN-y-induced iNOS mRNA levels. This is due to decreased iNOS gene transcription and iNOS mRNA stabihty. 

Cortexolone (4-pregnene-17,21-diol-3,20-dione), a partial agonist of the glucocorticoid receptor, and RU 38 486 [17P-hydroxy-lip-(4-dimethylamino-phenol) 17a-(prop-l-ynyl)estra-4,9-diene-3-one], a pure antagonist, were able to modulate and partially inhibit the suppressive effect of dexamethasone on the induction of NO2 in specific pathogen-free male Wistar rat alveolar macrophages (Jorens et al. 1992). 

---

Dewaxing, catalytic Dewaxing process Dewaxing processes Dexamethasone... 

Fluoro-llb,21-dihydroxy-16a-methyl-21-(phosphonooxy)-pregna-l,4-diene- 3,20-dione, disodium salt. See Dexamethasone sodium phospate. 

Fluoro-llb,17,21-trihydroxy-16a-methylpregna-l,4-diene-3,20-dione. See Dexamethasone. 

Glucocorticoids have been shown to inhibit gene transcription of other proteins involved in the inflammatory process, including the key inflammation mediators called cytokines (IL-1, IL3—6, IL8, GM-CSF, TNFa) (10,58,63—65). Steroids have been also shown to suppress the formation of cytokine receptors (10) dexamethasone, in particular, downregulates gene transcription of angiotensin II type 2 receptors (66). 

Research conducted by Simons using antiglucocorticoids, including compounds which covalentiy bind to the GR (124), eg, dexamethasone 21-mesylate, has better defined the stmcture and function of the GR. Spiro C-17 oxetanes have shown potent antiglucocorticoid activity in whole cell systems (125,126). 

The natural compounds cortisol [50-23-7], cortisone [53-06-5], and corticosterone [50-22-6] vary only slightly in stmctures and pharmacologic properties (see Steroids). The synthetic analogues inmore modem practice, prednisolone [52438-85-4], dexamethasone [50-02-2], triamcinolone [124-94-7], and betamethasone have greater antiinflammatory potency, and their effects on sodium retention tend to be less severe. 

Commercially available electrotransport systems are bulky and limited to acute appHcations (96). One example, the Drionic system used for the treatment of hyperhidrosis (excessive perspiration), is presoaked in water for 30 min before each 20- to 30-min treatment. Another system, the Phoresor, approved for the deHvery of Hdocaine [137-58-6] for local anesthesia, and of dexamethasone [50-02-2] for treatment of local inflammation such as bursitis or tendinitis, is powered by a 9 V replaceable battery and features a disposable, fiHable dmg electrode. 

Tolrestat (28) is a long-acang aldose reductase inhibitor useful in the prophylaxis of diabetic neuropathy, retinopathy, and cataracts [24 25] Lastly, the intro-ducuon of fluorine into steroids probably ushered in the modem era of fluonnated drugs Many commercial products were introduced [2] Typical of the products are the anti inflammatory glucocorticoids dexamethasone (29 X = F, Y = H), para-methasone (29, X = H, Y = F), and flumethasone (29, X = H, Y = F)... 

Dexamethasone j, 199 Dexbrompheni ramine 77 Dexchlorpheni ramine 1, 77 Dexivacaine 95 Dexnorgestrel acetime 152... 

Dexamethasone bovine tissue liq-liq extraction phenyl silica CN UV 29... 

E. G. McEauglilin and J. D. Henion, Determination of dexamethasone in bovine tissues by coupled-column normal-phase liigh-performance liquid cliromatography and capil-laiy gas chromatography-mass specti ometiy , 7. Chromatogr. 529 1-19 (1990). 

The preparation of dexamethasone acetate is described in U.S. Patent 3,007,923 as follows. 1.5 cc of dimethylformamide and 1.5 cc of anhydrous hydrofluoric acid are admixed and... 

---