Ozone induces glucose intolerance and systemic metabolic effects in young and aged Brown Norway rats.

Air pollutants have been associated with increased diabetes in humans. We hypothesized that ozone would impair glucose homeostasis by altering insulin signaling and/or endoplasmic reticular (ER) stress in young and aged rats. One, 4, 12, and 24 month old Brown Norway (BN) rats were exposed to air or ozone, 0.25 or 1.0 ppm, 6 h/day for 2 days (acute) or 2 d/week for 13 weeks (subchronic). Additionally, 4 month old rats were exposed to air or 1.0 ppm ozone, 6 h/day for 1 or 2 days (time-course). Glucose tolerance tests (GTT) were performed immediately after exposure. Serum and tissue biomarkers were analyzed 18 h after final ozone for acute and subchronic studies, and immediately after each day of exposure in the time-course study. Age-related glucose intolerance and increases in metabolic biomarkers were apparent at baseline. Acute ozone caused hyperglycemia and glucose intolerance in rats of all ages. Ozone-induced glucose intolerance was reduced in rats exposed for 13 weeks. Acute, but not subchronic ozone increased α2-macroglobulin, adiponectin and osteopontin. Time-course analysis indicated glucose intolerance at days 1 and 2 (2>1), and a recovery 18 h post ozone. Leptin increased day 1 and epinephrine at all times after ozone. Ozone tended to decrease phosphorylated insulin receptor substrate-1 in liver and adipose tissues. ER stress appeared to be the consequence of ozone induced acute metabolic impairment since transcriptional markers of ER stress increased only after 2 days of ozone. In conclusion, acute ozone exposure induces marked systemic metabolic impairments in BN rats of all ages, likely through sympathetic stimulation.

Pharmacokinetics of flunixin meglumine in lactating cattle after single and multiple intramuscular and intravenous administrations.

The pharmacokinetics of flunixin were studied in 6 adult lactating cattle after administration of single IV and IM doses at 1.1 mg/kg of body weight. A crossover design was used, with route of first administration in each cow determined randomly. Plasma and milk concentrations of total flunixin were determined by use of high-pressure liquid chromatography, using an assay with a lower limit of detection of 50 ng of flunixin/ml. The pharmacokinetics of flunixin were best described by a 2-compartment, open model. After IV administration, mean plasma flunixin concentrations rapidly decreased from initial concentrations of greater than 10 micrograms/ml to nondetectable concentrations at 12 hours after administration. The distribution phase was short (t1/2 alpha, harmonic mean = 0.16 hours) and the elimination phase was more prolonged (t1/2 beta, harmonic mean = 3.14 hours). Mean +/- SD clearance after IV administration was 2.51 +/- 0.96 ml/kg/min. After IM administration, the harmonic mean for the elimination phase (t1/2 beta) was prolonged at 5.20 hours. Bioavailability after IM dosing gave a mean +/- SD (n = 5) of 76.0 +/- 28.0%. Adult, lactating cows (n = 6) were challenge inoculated with endotoxin as a model of acute coliform mastitis. After multiple administration (total of 7 doses; first IV, remainder IM) of 1.1 mg/kg doses of flunixin at 8-hour intervals, plasma flunixin concentrations were approximately 1 microgram/ml at 2 hours after each dosing and 0.5 micrograms/ml just prior to each dosing. Flunixin was not detected in milk at any sampling during the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunoassay detection of drugs in racing horses. III. Detection of morphine in equine blood and urine by a one step ELISA assay.

A one step enzyme-linked immunosorbent assay (ELISA) test for morphine was evaluated as part of a panel of pre- and post-race tests for narcotic analgesics in racing horses. This ELISA test is very sensitive to morphine with an I-50 for morphine of about 400 pg/ml. The test is also rapid, and ten samples, a normal pre-race complement, can be analyzed in about thirty minutes. The test can be read with an inexpensive spectrophotometer, or even by eye. The test readily detects the presence of morphine or its metabolites in equine blood for up to six hours after administration of sub-therapeutic doses. The antibody also cross-reacts with hydromorphone, orymorphone, nalorphine, levorphanol, and codeine, and the test either can detect or is likely to detect these drugs in blood or urine shortly after their administration to horses. As such this test is capable of dramatically improving the speed and efficacy of both pre-race and post-race testing for morphine and its congeners in racing horses. On initial introduction into post-race urine screening this test flagged 18 of 166 samples positive for opiates, and 13 of these samples were confirmed positive for opiates by mass spectrometry.

Immunoassay detection of drugs in horses. I. Particle concentration fluoroimmunoassay detection of fentanyl and its congeners.

We investigated the use of particle concentration fluorescence immunoassay (PCFIA) as a technique for drug detection in racing horses. The test was constructed from an antiserum to a carboxyfentanyl-BSA conjugate and carboxyfentanyl linked to b-Phycoerythrin. Using these reagents and a PCFIA apparatus levels of fentanyl as low as 0.1 ng/ml could be detected by the assay. In addition, cross-reactivity studies on this assay showed that the anti-serum cross-reacted well with carfentanil, sufentanil and the methylated analogs of fentanyl. We therefore evaluated the ability of these agents to produce pharmacological effects in the horse and the ability of this test to detect pharmacologically significant doses of this drug in racing horses. All of these agents produced good locomotor responses in horses at doses of between 0.1 and 10 micrograms/kg. Of these agents, carfentanyl was the most potent followed by 3-methylfentanyl, sufentanyl, alpha-methylfentanyl, and fentanyl. Similarly, when these agents were administered to horses at doses sufficient to produce a pharmacological response, all produced sufficient inhibition of fluorescence in the PCFIA system to enable their detection in post-race urines from these horses. Since PCFIA is a much faster technique than radioimmunoassay, is of approximately similar sensitivity, and requires much less instrumentation we concluded that this technique holds considerable promise as an equine drug testing technique.

Disposition of [4-14C]mofebutazone in the rat.

The absorption and elimination of radioactivity after the oral or intraperitoneal administration of[4-14C]mofebutazone was studied in rats. The blood concentration of radioactivity reached a maximum after about 0.7 h, fell rapidly until about 2 h, and then declined slowly. There was sometimes a second peak between 3-6 h. Elimination of radioactivity in urine and feces was extensive and rapid. Over a 24 h period, 73% of the orally administered radioactivity was eliminated in the urine and 15% in the faeces; most of this was eliminated during the first 8 h (89% of the urine radioactivity, 56% of the faeces radioactivity). In anaesthetized rats with cannulated bile ducts, 94% of the intraperitoneally injected radioactivity was eliminated in the bile over a 6 h period. Most of the radioactivity (about 85%) eliminated in the bile and the urine was in the form of a glucuronide and only small amounts less than 10%, was in the form of mofebutazone.

The identification of sympathomimetic amines by Raman spectroscopy.

This study was undertaken to explore the feasibility of using Raman spectroscopy as a means of identifying drugs in the forensic laboratory. Raman spectra of a group of sympathomimetic amines, in pure form and in pharmaceutical preparations, were obtained and compared; group similarities and individual differences were found, and satisfactory identifications could be made. Water solutions as well as solids were examined. The procedure is rapid, sensitive, simple, and non-destructive.

Normal canine lipid profiles and effects of experimentally induced pancreatitis and hepatic necrosis on lipids.

Normal lipid profiles (total lipids, total cholesterol, phospholipids, free fatty acids, triglycerides, and lipoproteins) were determined in 23 clinic-reared dogs and 26 client-owned dogs. A significantly higher concentration of cholesterol was found in client-owned dogs as compared with clinic-reared dogs. Hepatic necorosis, induced by CCl4, resulted only in a significant decrease in triglycerides. Acute pancreatitis, induced by major and minor pancreatic duct ligations, resulted in a significant increase in free fatty acids and low-density lipoprotein with a decrease in high-density lipoprotein-2.

Hydroxamic acids as colorimetric reagents.

Thirty-three hydroxamic acids and three N-substituted hydroxamic acids or structurally similar compounds have been studied as possible colorimetric reagents for metal ions. They were tested with 78 ions under varying conditions of acidity and basicity. Aliphatic, substituted aliphatic, aromatic, substituted aromatic, and heterocyclic hydroxamic acids were represented in the compounds studied. An attempt was made to correlate the activity towards metal ions with variations in the molecular structure of the hydroxamic acids. The studies with C-substituted hydroxamic acids indicate that the preferential formation of a colour or a precipitate depends on pH, the solvent, and reagent concentration, and is not a function of the presence or absence of a substituent on the nitrogen atom. A number of the compounds offer promise of being useful colorimetric reagents under proper reaction conditions.