摘要:

Autoradiography of [3H] quinuclidinyl benzilate was used to demonstrate the distribution of muscarinic acetylcholine binding in the spinal cord of sheep. Binding was confined to the grey matter of the cord, and was most densely distributed in the substantia gelatinosa region of the dorsal horn, the lamina X region around the central canal, the intermediolateral columns and in various regions of the ventral horn. The use of specificM/1 andM2 receptor subtype ligands, pirenzipine and 4‐DAMP indicated that both receptor subtypes were present in most regions of dense bindin

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1991.tb00847.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Oxytetracycline pharmacokinetics and tissue distribution were studied in rainbow trout following bolus i.v. administration at 5 mg/kg. The mean serum (log) drug concentration data were plotted against time (linear). The decay curve was described by a three‐component exponential decay function and a three‐compartment model. Thet1/2of rapid distribution was 0.9 h, the t1/2of the slow distribution was 5.9h and thet1/2elimination was 81.5 h. Clearance was 25.4 ml/kg/h andVd(area)2988 ml/kg. Regression analysis of the serum levels for the three intervals, 0.5‐2.0 h, 6.0‐18.0 h, and 24‐96 h, indicated that the rates of decay for each interval were 0.6151 h‐1, 0.0564 h‐1and 0.0088 h‐1respectively. Rates of equilibration between tissues and serum were determined. Kidney equilibrated the fastest witht1/2to equilibration of 1.1h for H (anterior) kidney and 1.98h for P (posterior) kidney. The highest drug levels were found in the liver and the lowest we

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1991.tb00848.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

The intramuscular (IM) and oral (PO) disposition of enrofloxacin, a new fluoroquinolone antimicrobial drug, were evaluated in African grey parrots. Peak enrofloxacin concentration, mean (± SEM), at 1h following a 15‐mg/kg IM dose was 3.87 (± 0.27) μg/ml and declined with a mean residence time of 3.05 h. Peak enrofloxacin plasma concentrations at 2 to 4h following oral doses of 3, 15, and 30 mg/kg were 0.31 (± 0.11), 1.12 (± 0.11), and 1.69 (± 0.23) μg/ml, respectively, and declined with a mean residence time of 3.44‐5.28 h. The relative bioavailability of the 15‐mg/kg oral dose was 48%. An equipotent metabolite, ciprofloxacin, was detected in plasma at concentrations ranging from 3 to 78% of those of enrofloxacin. Enrofloxacin concentrations and area under the curve were significantly lower, the mean residence time significantly shorter and the ciprofloxacin/enrofloxacin ratios higher, following 10 days of oral treatment at 30 mg/kg every 12 h. Following 10 days of treatment, no significant biochemical changes were noted; however, polydipsia and polyuria occurred in treated birds, but resolved quickly upon discontinuation of enrofloxacin administration. These studies indicate that a rational starting dose for enrofloxacin in psittacines (7.5‐30 mg/kg BID) should be higher than those in other do

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1991.tb00849.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

The pharmacokinetics of methimazole (MMI) administered intravenously and orally were determined in six adult domestic shorthaired cats. There was no significant difference between mean serum MMI concentrations after oral and i.v. administration by 30 min post‐MMI administration, indicating relatively rapid and complete absorption of the drug. The bioavailability of MMI ranged from 27% to 100% (mean=81.1±11.4%). The mean serum elimination half‐life was 6.6±2.0 h, with a wide range of values (1.9h to 15.1h). After repeat i.v. administration of MMI following 2 weeks of oral administration of the drug, no significant difference was found between mean serum concentrations after single‐dose and multiple‐dose administration. No significant change in serum elimination half‐life or total body clearance was found after multiple‐dose administration of MMI. Two cats with the longest half‐lives (9.9h and 15.1h), however, did exhibit markedly shortert1/2, values (3.5h and 3.3h, respectively) after multiple‐dose administration. Values for central and steady state volumes of distribution also decreased after multiple‐dose administration, possibly indicating saturation of thyroid uptake of MMI with chronic administration. These results indicate that MMI has good oral bioavailability and has a longer mean serum elimination half‐life than propylthiouracil, the other anti‐thyroid drug that has been evaluated in cats. Although no significant change in mean values occurred after multiple‐dose administration of MMI, drug‐induced acceleration of metabolism may occur in some cats after l

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1991.tb00850.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

The pharmacokinetic disposition of 2‐mercaptopropionylglycine (2‐MPG) given as a single intravenous injection and/or as a single oral dose was studied in 9 normal and 13 cystinuric dogs. After intravenous injection of approximately 10 or 20mg/kg body weight the pharmacokinetics were best described by a three‐exponential function. The first phase involved a distribution process apparently including establishment of drug‐plasma protein and drug‐tissue binding. The second phase involved rapid renal elimination and 60% of the drug was excreted within 3h of administration. There was also a slow terminal third phase with a long half‐life after both intravenous (t1‐2=23h) and oral (t1/2=22h) administration. No dose dependency was observed. A deep pool of reversibly tissue‐bound 2‐MPG was indicated by a Vssof 3.3±0.9l/kg body weight and the long terminal elimination phase. Total clearance was estimated as 4.1±0.9ml/min/kg body weight. 2‐MPG was eliminated mainly by renal excretion, but there was a difference in recovery of dose between normal and cystinuric dogs. During the first 24h after intravenous and oral administration, 69% and 54%, respectively, of the drug was recovered in the urine of normal dogs. The corresponding figures in cystinuric dogs were 44% and 29%, respectively. The absolute bioavailability (FAUC) was

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1991.tb00851.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

The effect of acute inflammation on oxytetracycline (OTC) distribution was studied in a tissue cage model in calves. An acute inflammatory reaction was induced in tissue cages by injecting lipopolysaccharide (LPS) fromSalmonella typhimurium. The distribution of OTC to tissue cage fluid (TCF) was also compared with distribution to fluid from granuloma pouches (GPF). Tissue from LPS‐injected cages showed histological changes indicating an acute inflammatory reaction. Concentrations of OTC were higher in LPS cages than in controls; at 1, 2, 4 and 10h the difference was statistically significant (P<0.05). Numerically the overall elimination rate constant(kel) was larger, elimination half‐life(t1/2) shorter, peak concentration(Cmax) higher, and time of peak concentration(Tmax) shorter in LPS cages than in controls. The area under the curve(AUC)of OTC was greater and the ratioAUCTCF/AUCserumwas higher in LPS cages than in controls. Although statistically significant differences were not found for all the pharmacokinetic parameters, it was concluded that distribution to and elimination from LPS cages were both faster than in controls. Concentration‐time profiles of OTC were similar in TCF and GPF in that concentrations were lower and elimination was more prolonged than in serum. Levels were higher in GPF than in TCF up to 3h after injection; thereafter the relationship was reversed. Distribution to and elimination processes from GPF appeared to be faster than from TCF as numericallykelwas higher,t1/2shorter andTmaxshorter in GPF than in TCF. It was concluded that the granuloma pouch model and the tissue cage model have similarities in distribution and elimination patterns and that differences are most probably due to differences in the ratio of the surface area to the v

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1991.tb00852.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

In this note it is argued that the principal characteristic of the confidence intervals proposed by Bartoszynski&Powers (1990) is not primarily the fact that they are of minimum length but that they are Bayesian highest posterior density intervals. A simple iterative process for determining the ends of the interval is presented.

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1991.tb00853.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Danofloxacin is a new fluoroquinolone antibacterial, developed specifically for veterinary use. Itsin vitroactivity and pharmacokinetic properties have been investigated to assess its potential for use in the therapy of respiratory disease in cattle. The minimum inhibitory concentration of danofloxacin against 90%(MIC90) of contemporary European and North American field isolates ofPasteurella haemolytica, Pasteurella multocidaandHaemophilus somnus, the most important bacterial respiratory pathogens of cattle, was 0.125μg/ml. The plasma and lung kinetics of danofloxacin following parenteral administration of 1.25mg/kg were evaluated in two studies. Danofloxacin was rapidly absorbed following intramuscular and subcutaneous injection and bioavailability was virtually complete (101% and 94% respectively). Plasma concentration profiles of danofloxacin were similar for intramuscular and subcutaneous routes with no significant differences in the area under the plasma concentration‐time curves(AUC)following one, three or five consecutive daily doses, although slightly higher peak plasma concentrations were achieved by the intramuscular route. Following intramuscular administration, the mean peak lung concentration of danofloxacin was 4.1 times greater than that of plasma. Similarly, theAUCfor lung tissue was 3.7 times greater than that for plasma. These data indicate that danofloxacin should be particularly appropriate for the therapy of bacterial respiratory disease in catt

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1991.tb00854.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

The effect of furosemide administration (1mg/kg body weight, i.v.) on plasma and blood volumes in 6 intact and 4 splenectomized horses was measured using Evans blue dye dilution, hematocrit, and hemoglobin and plasma total solids concentrations. Body weight decreased by 33.6±3.3 and 33.7±0.8g/kg 4h after furosemide administration to intact and splenectomized mares, respectively. Plasma volume, estimated by Evans blue dye dilution, was reduced by 8.3±3.3% (mean±SE) 4h after furosemide administration. The reduction in plasma volume was first detectable 5‐10 min after furosemide administration and was greatest 15‐30 min (13.0±0.8%) after dosing. This study demonstrates that furosemide produces significant and rapid reductions in plasma volume in horses. These decreases in plasma volume only partially resolve 4h after furosemide admini

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1991.tb00855.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1991.tb00856.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY