Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We describe a liquid chromatographic screening procedure for the detection of stimulant laxatives in urine. A 2-ml urine sample was incubated with 500 U of beta-glucuronidase for 2 h at 60 degrees C. The sample was acidified with sodium acetate (pH 5.0) and extracted with 5 ml of an isopropanol-chloroform (1:9) mixture. The organic layer was cleaned up further by washing with 5 ml disodium hydrogen-phosphate (pH 7.5) before being transferred to a conical tube and evaporated to dryness. The residue was reconstituted in 100 microliters mobile phase and 3 microliters were injected onto a Hewlett-Packard Hypersil ODS (5 microns) column. The ultraviolet absorbance of the eluent was monitored at 225 nm. Rhein, bisacodyl diphenol, bisoxatin diphenol, phenolphthalein, bisacodyl, bisoxatin and danthron all eluted within 6 min. The screen was evaluated using urine specimens obtained from 19 patients who claimed they had taken one or more of the laxatives under consideration within the past 48 h. Only two patients who claimed to have taken Coloxyl and Danthron showed negative results. Eighteen of twenty laxatives (90%) taken by the patients were detected and their identity verified by plotting post-run ultraviolet spectra. We therefore conclude that the screen is sufficiently reliable to be of help in the early detection of surreptitious abusers of stimulant laxatives.
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PMID:Screening procedure for stimulant laxatives in urine using high-performance liquid chromatography with diode array detection. 323 41

The effects of graded doses of zinc sulfate pretreatment on reserpine-induced gastric ulceration and on lysosomal fragility both in vivo and in vitro, were studied in rats. Reserpine treatment (5 mg/kg, i.p., 18 h before sacrifice) induced marked gastric glandular ulceration and elicited the release of free beta-glucuronidase from lysosomes in the gastric mucosa. A similar effect on release of this enzyme from isolated rat hepatic lysosomes was observed after in vitro incubation with reserpine. Zinc sulfate (22, 44 or 88 mg/kg, i.p., 30 h before reserpinization, or 10(-3) M in vitro) inhibited the reserpine-induced response, and zinc sulfate alone (10(-11)--10(-3) M) also stabilized lysosomal membrane permeability to beta-glucuronidase. No direct effect of zinc or reserpine on purified beta-glucuronidase activity was observed. In conclusion, it is postulated that the stabilizing effect of zinc on lysosomal membranes, as manifest by reduced release of beta-glucuronidase from isolated lysosomes, is one of the protective mechanisms of zinc against reserpine-induced ulceration.
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PMID:Reserpine-induced gastric ulcers: protection by lysosomal stabilization due to zinc. 737 12

A liquid chromatographic (LC) method was developed for the determination of flunixin (FNX) in raw bovine milk. The milk was acidified and mixed with silica gel, and the mixture was packed into a chromatographic column. The column was defatted with water-saturated dichloromethane-hexane (30 + 70, v/v), and the analyte was eluted with EtOAc. The EtOAc extract was washed with water at pH 3.5, the water was discarded, and the EtOAc layer was then extracted with 0.1M NaOH. The aqueous layer was drained, passed through a primed C18 solid-phase extraction (SPE) column, and eluted with EtOAc. The EtOAc layer was dried under N2, taken up in a solution of MeOH-(5 mM tetrabutylammonium [TBA]-H2PO4 + 2 mM NaOH) (50 + 50), sonicated, and filtered. FNX was determined by LC using a C18 column (ODS Hypersil), a mobile phase mixture of 58% A (MeOH) and 42% B (5 mM TBA-H2PO4 + 2 mM NaOH), and a diode-array ultraviolet detector at 285 nm. FNX was determined in raw milk at 5 spiking levels (5, 10, 20, 40, and 80 ng drug/mL milk). Absolute recoveries ranged from 69.6 to 74.4%, and relative standard deviations ranged from 1.1 to 6.9%. The limit of quantitation was 1.7 ng drug/mL milk. A lactating cow was dosed intravenously (2.2 mg/kg) with flunixin meglumine (Banamine) to generate incurred milk residues. FNX residues ranged from 7.34 ng/mL at 16 h postdose to 1.74 ng/mL at 24 h postdose. Both levels were obtained with additional beta-glucuronidase treatment (almost no incurred drug was detected at these low levels without the enzyme treatment).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Determination of flunixin in milk by liquid chromatography with confirmation by gas chromatography/mass spectrometry and selected ion monitoring. 758 Mar 36