The condensed tannin present in cotton mill dust profoundly alters the functional capabilities of resident alveolar macrophages. Previous studies from this laboratory have shown that in vitro exposure of rabbit resident alveolar macrophages to condensed tannin significantly inhibits the ability of these cells to produce reactive oxygen intermediates or to ingest particles. In the present study, we demonstrate that condensed tannin also alters arachidonic acid (C20:4) metabolism in these cells. Exposure of rabbit resident alveolar macrophages to condensed tannin results in the time- and dose-dependent release of C20:4 from the membrane phospholipids. The release of C20:4 occurred only at tannin concentrations greater than 25 micrograms/ml and was maximal 90 min after the onset of exposure. The EC50 for release was 75 micrograms/ml. Exposure to 100 micrograms/ml tannin resulted in the release of 20 +/- 3% of the [14C]C20:4 incorporated in the cell membrane. In comparison, exposure to 160 micrograms/ml zymosan resulted in the release of 14 +/- 4% of the [14C]C20:4. For both tannin and zymosan, phosphatidylcholine and phosphatidylinositol were the principal sources of the released C20:4. Approximately 63% of the C20:4 released after zymosan stimulation was further metabolized, mainly via the cyclooxygenase pathway. The major metabolites were 6-keto-prostaglandin F1 alpha, prostaglandin F2 alpha, and prostaglandin E2. In contrast, only 24% of the C20:4 released by tannin was subsequently further metabolized. The metabolites formed were essentially evenly distributed between products of the cyclooxygenase pathway and the lipoxygenase pathway. Exposure of alveolar macrophages to 50 micrograms/ml tannin for 30 min reduced the ability of the cells to subsequently incorporate C20:4 by 50 to 70%. In contrast, exposure of the cells to 160 mg/ml zymosan for 30 min had only a minimal effect on the subsequent ability of these cells to incorporate C20:4. These results indicate that tannin promotes C20:4 release, at least in part, by inhibiting its reacylation back into phospholipids, a mechanism that differs from that of zymosan.
A chemically modified electrode (CME) for use in the amperometric detection of the copper protein ceruloplasmin was constructed by electropolymerizing a polyaniline coating onto gla5sy carbon. The resultant CME, used in liquid chromatographic detection, gave an electrocatalytic response for ceruloplasmin reduction that could be employed directly by itself or could be greatly enhanced by the addition of Fez+ to the mobile phase. Optimum detection was achieved at an applied potential of -0.10 V vs. Ag/AgCl and with 1 mM Fe2+ in the mobile phase. The detection limit obtained under these conditions was 2 pmol injected, and the response was linear for concentrations at least 2 orders of magnitude higher. The CME retained more than 90% of its initial response to ceruloplasmin over 30 hours of continuous exposure to the chromatographic flowstream. In practice, the liquid chromatography CME response was sensitive and selective enough to permit quantitation of physiologically relevant levels of ceruloplasmin in human serum with no sample pretreatment other than preinjection filtration.
Commercially manufactured wet/dry autoinjectors containing atropine in solution and powdered HI-6 were evaluated using HPLC for consistency of drug delivery with various solvation times and stability of drugs postsolvation at a temperature of 40 degrees C. Three configurations of autoinjector were tested. System A (SYS A), with a specified mixing time of 5 sec, delivered a volume of 3.0 ml containing 1.86 mg of atropine sulfate and 443 mg of the bispyridinium oxime HI-6 dichloride. System B1 (SYS B1) and System B2 (SYS B2), with specified mixing times of 40 sec, delivered volumes of 2.3 ml containing 2.13 and 2.06 mg atropine citrate and 424 and 545 mg HI-6 dichloride, respectively. Average coefficients of variation for SYS A were 3.4% for atropine and 5.8% for HI-6 and for SYS B1 and B2 were 5.2% for atropine and 7.0% for HI-6 determinations. Stored from 3 to 14 days at 40 degrees C after the autoinjector contents were mixed, SYS A delivered 1.77 mg atropine sulfate and SYS B1 and B2 delivered 2.02 mg atropine citrate. The delivery of HI-6 dichloride decreased with a half-life of 34 days for SYS A, 39 days for SYS B1, and 32 days for SYS B2. This resulted in a decrease to 90% of the respective day 0 amount after 4 (SYS A) or 5 (SYS B1 or B2) days.
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