bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of rumination in sheep by α‐adrenoreceptor antagonists
Authors: NICHOLSON T. , OSMAN T. E. A. , BELKHIRI M. 
Published: April 2008

Nicholson, T., Osman, T.E.A. & Belkhiri, M. Inhibition of rumination in sheep by α‐adrenoreceptor antagonists.J, vet. Pharmacol. Therap. 11, 276–282, 1988.Rumination activity was recorded in sheep during a period of 3 h. The amount of rumination occurring in 30 min following the intravenous injection of an α blocking drug (prazosin, 0.1 mg/kg) and an a2 blocking drug (idazoxan, 0.1 mg/kg) was reduced compared with control days when saline was given. The observation that rumination can be stimulated by a rapid, intravenous dose of adrenalin was confirmed. The induction of rumination by adrenalin was prevented by these α ‐adrenoreceptor antagonists given singly or together at the dose rate mentioned. These findings are discussed in the light of knowledge that normal reticulo‐ruminal motility and food intake can be inhibited by stimulation of α ‐adrenoreceptors.
Parainfluenza‐3 virus‐induced enhancement of histamine release from calf lung mast cells – effect of levamisole
Authors: OGUNBIYI P. O. , BLACK W. D. , EYRE P. 
Published: April 2008

Ogunbiyi, P.O., Black, W.D. & Eyre, P. Parainfluenza‐3 virus‐induced enhancement of histamine release from calf lung mast cells – effect of levamisole.J. vet. Pharmacol. Therap.11, 338–344.Clinically healthy calves were divided into five groups. Group 1 served as control; Group 2 received levamisole (LEV), 3 mg/kg, s.c; Group 3 was aerosolized with parainfluenza‐3 virus (PI‐3); Group 4 received LEV and PI‐3 and Group 5 was inoculated with Pasteurella haemolytica. They were killed 6 days after virus exposure or 5–6 days after bacterial inoculation. Lung mast cells were prepared by enzymatic treatment. Mast cell histamine (HIST) release was assayed spectro‐fluorometrically. Total HIST (&#x006d;̈g/g) in mast cells was as follows (x̄± SEM): control (5.30 ± 0.26); LEV (5.27 ± 0.31); PI‐3 (6.37 ± 0.65); LEV ± Pl‐3 (6.21 ± 0.51); P. haemolytica (7.06 ± 0.85). Spontaneous HIST release was as follows (% total, x̄± SEM): control (10.38 ± 1.09), LEV (11.95 ± 2.13), PI‐3v (73.57 ± 11.97), PI‐3v ± LEV (19.50 ± 3.03), and P. haemolytica (70.59 ± 5.94). Calcium ionophore A23187 (5 times 10‐6 M) ‐induced release (% total, x̄± SEM) was: 51.53 ± 3.05, 50.02 ± 2.70, 83.91 ± 4.09, 75.21 ± 4.51 and 70.59 ± 6.91 for control, LEV, PI‐3, LEV ± PI‐3 and P. haemolytica groups, respectively. Both virus and bacteria increased HIST content of lung mast cells and enhanced ionophore‐induced release. Levamisole significantly reduced spontaneous HIST release in virus‐infected calves but had no effect on ionophore‐induced release. Results suggest a significant role for HIST in pathogenesis of bovine microbial pneumonia and that LEV probably does not modulate non‐immunologic release of HIST from bovine lungs.
Comparative effects of etomidate and its fluoro analogue, R 8110 on testicular, adrenal and ovarian steroid biosynthesis
Authors: COSTER R. DE , WOUTERS W. , BEERENS D. , HAELTERMAN C. , DOOLAEGE R. , GOEMINNE N. , KREKELS M. 
Published: April 2008

De Coster, R., Wouters, W., Beerens, D., Haelterman, C, Doolaege, R., Goeminne, N. & Krekels, M. Comparative effects of etomidate and its fluoro analogue, R 8110 on testicular, adrenal and ovarian steroid biosynthesis. J. vet. Pharmacol. Therap.11, 345–353.The effects, of etomidate and of its fluoro analogue, R 8110, on adrenal, testicular and ovarian steroid biosynthesis were compared using cultures of guinea‐pig adrenal, rat adrenal capsular, rat testicular and rat ovarian granulosa cells. At a concentration of 100 nM, etomidate inhibited the adrenal 11‐hydroxylation of glucocorticoid and mineralocorticoid biosyntheses, producing a decrease in Cortisol and corticosterone and an accumulation of 11‐deoxycortisol and 11‐deoxycorticosterone in guinea‐pig adrenal and rat capsular adrenal cell suspensions, respectively. At higher concentrations (> 10‐6 M), etomidate also inhibited ovarian oestradiol production, testicular androgen formation and ovarian progesterone synthesis. The latter action suggests an effect on ovarian aroma‐tase, on testicular 17a/17,20‐lyase activities and Finally on cholesterol side‐chain cleavage. The fluoro analogue of etomidate, R 8110, was ten times less potent as an inhibitor of 11‐hydroxylation and affected progesterone formation only slightly in adrenal cell suspensions. Testosterone production was less affected by R 8110 than by etomidate. The increase of progestins suggests that the 17a/ 17,20‐lyase activities are the most sensitive testicular enzymatic reactions to R 8110. For inhibition of ovarian oestradiol production, R 8110 was twenty times more potent than etomidate.
Gizzard ulceration in chicks fed cysteamine alone or in combination with a histamine H2‐receptor antagonist
Authors: ZAVY M. T. , LINDSEY T. O. , HEDDE R. D. 
Published: April 2008

Zavy, M.T., Lindsey, T.O. & Hedde, R.D. Gizzard ulceration in chicks fed cysteamine alone or in combination with a histamine H2‐receptor antagonist. J. vet. Pharmacol. Therap. 11, 362–373.A study was carried out to evaluate the effect of cysteamine‐HCl administration on gizzard ulceration and growth performance in broiler chicks. The effectiveness of the histamine H2‐receptor antagonist, SKF 93479, in preventing gizzard ulcerations when given in combination with cysteamine‐HCl was also examined. In the initial experiment cysteamine‐HCl at the level of 2400 mg/kg of the diet caused severe gizzard ulceration and mortality and decreased feed intake and growth in chicks. The effect was not seen when cysteamine‐HCl was administered at 600 or 1200 mg/kg of the diet. In Experiment 2 broiler chicks administered cysteamine‐HCl at 1800 mg/kg of the diet had an increased incidence of gizzard ulceration and decreased growth performance. The severity of gizzard lesions and the depression of growth performance were not as great as in the group in Experiment 1 which received the 2400 mg/kg level of cysteamine‐HCl. Addition of the H2 antagonist SKF 93479 at 54 mg/kg of the diet had no effect on improving gizzard ulcer score or growth performance in chicks which received cysteamine‐HCl at the 1800 mg/kg of the diet level. From these data it appears that the administration of ulcerogenic levels of cysteamine‐HCl in the chicken may involve a more complex pathogenesis in which factors other than acid hypersecretion are involved.
Determination of the acute oral toxicity of theophylline in conscious dogs
Authors: MUNSIFF I.J. , MCKIERNAN B.C. , NEFF‐DAVIS C. A. , KORITZ G. D. 
Published: April 2008

Munsiff, I.J., McKiernan, B.C., Neff‐Davis, C.A. & Koritz, CD. Determination of the acute oral toxicity of theophylline in conscious dogs. J. vet. Pharmacol. Therap. 11, 381–389.The purpose of this study was to define the minimum toxic concentrations and clinical signs of theophylline toxicity in healthy, conscious dogs. Five dogs were dosed orally in a five‐way crossover design with sustained release theophylline (Theo‐Dur® tablets, Key Pharmaceuticals) at 0, 20, 40, 80, and 160 mg/kg. They were observed for a 9‐h period for clinical signs of toxicity which had been previously determined in a pilot study. These signs included sinus tachycardia and central nervous stimulation (manifested as restlessness, excitement, or vomition). The Physiotel® radiotransmitter telemetry system was used for the acquisition of the heart rate and ECG. Blood samples were obtained every hour for theophylline determination by high pressure liquid chromatography. The results showed that toxicity occurs at higher theophylline plasma concentrations in the dog (37–60 &#x006d;̈g/ml) as compared to man (> 20 &#x006d;̈g/ml) when dosed orally. Since current dosage regimens in dogs are designed to maintain trough‐peak theophylline plasma concentrations between 10 and 20 &#x006d;̈g/ml, the results indicate that the upper limit of this range appears to be safe in the dog.
Sedative and analgesic effects of medetomidine in dogs
Authors: VAINIO O. , VÄHA‐VÄHE T. , PALMU L. 
Published: April 2008

Vainio, O., Vähä‐Vahe, T. & Palmu, L. Sedative and analgesic effects of medetomidine in dogs. J. vet. Pharmacol. Therap.12, 225–231.The sedative and analgesic effects of medetomidine were studied in 18 laboratory beagles in a randomized cross‐over study which was carried out in a double‐blind fashion. Xylazine was included as a positive control and placebo as a negative control. Medetomidine was used at doses of 10, 30, 90 and 180 μg/kg i.m. compared to a dose of 2.2 mg/kg xylazine i.m. Parameters closely related to sedation were used to measure the degree of sedation. These were a posture variable (including evaluation of the dog's posture without external disturbance and resistance when laid recumbent) and a relaxation variable (including relaxation of the jaws, upper eyelids and anal sphincter). The First signs of sedation were recorded 1.5–3.5 min after administration of both drugs. The dogs sat down at 0.6–2.6 min post‐injection and became prone at 1.9‐5.9 min. Medetomidine dose‐dependently affected the posture of the dogs and the relaxation variable — the higher the dose, the stronger and longer lasting the effect recorded. The sedative effect of xylazine was comparable to a medetomidine dose of 30 μg/kg. The analgesic effect was assessed as changes in the response to superficial pain induced by electrical stimuli. The response threshold increased significantly with both drugs and the effect of medetomidine was dose‐dependent. The effects of the doses of 30 μg/kg medetomidine and 2.2 mg/kg xylazine did not differ significantly. In summary, medetomidine possessed an excellent sedative effect associated with analgesia in dogs.
The effect of clinical hepatic disease on the distribution and elimination of pethidine administered post‐operatively to dogs
Authors: WATERMAN A. E. , KALTHUM W. 
Published: April 2008

Waterman, A.E. & Kalthum, W. The effect of clinical hepatic disease on the distribution and elimination of pethidine administered post‐operatively to dogs. J. vet. Pharmacol. Therap. 13, 137–147.The pharmacokinetics of pethidine were investigated in dogs suffering from portosystemic vascular shunts and hepatic parenchymal disease. The drug was administered post‐operatively at a dose rate of 2.0 mg/kg either intravenously or intramuscularly. When the drug was given intravenously to dogs suffering from intrahepatic shunts, the elimination half life was 75.5 ± 4.2 min and the clearance rate was 29.0 ± 2.3 ml/kg min. When the drug was given intramuscularly its rate of absorption was very slow (57.9 ± 6.1 min) and the time taken to reach the maximum plasma concentration was long at 26.7 ± 6.4 min. The elimination half‐life for the intramuscularly administered drug was also very slow at 108.0 ± 13 min, reflecting the reduced ability of these dogs to metabolize and eliminate pethidine. These findings suggest that caution should be exercised in the administration of pethidine to dogs suffering from hepatic dysfunction. In particular, the slower rate of absorption should be remembered in judging whether or not maximum effects have been achieved and the longer elimination half‐life indicates the need to extend the intervals between repeat doses of this analgesic. A. E. Waterman, Department of Veterinary Surgery, University of Bristol, Langford House, Langford, Bristol BS18 7DU, UK.
Gastric retention of enteric‐coated aspirin tablets in beagle dogs
Authors: NAP R. C. , BREEN D.J. , LAM T. J. G. M. , De BRUYNE J.J. 
Published: April 2008

Nap, R.C., Breen, D.J., Lam, T.J.G.M. & de Bruyne, J.J. Gastric retention of enteric‐coated aspirin tablets in beagle dogs. J. vet. Pharmacol. Therap. 13, 148–153.Administration of acetylsalicyclic acid (ASA) in the dog may cause gastric mucosal damage. Enteric‐coated tablets protect the canine stomach during oral ASA medication. A therapeutic plasma salicylate concentration can be attained using enteric‐coated ASA tablets at a dose rate of 25 mg/kg body wt, administered every 8 h. Six beagle dogs were given enteric‐coated ASA tablets (500 mg) orally, in a 5‐day cross‐over experiment on two different feeding regimens: i.e. feeding once daily (Group I) or 8 hourly (Group II). Results demonstrate that feeding regimen strongly influences the plasma salicylate concentration pattern. Subtherapeutic mean plasma salicylate concentrations were found in both groups. In Group II the standard deviation (SD) of the mean plasma salicylate concentration was larger than that of Group I. The minimal plasma salicylate concentration never reached detectable levels in Group II. In both groups large numbers of tablets were vomited. Gastric evacuation of the ASA tablets is comparable to indigestible solid particles; their removal was dependent on the interdigestive gastric motility. It is concluded that large enteric‐coated ASA tablets are not suitable for therapeutic use in small dogs. R. C. Nap, Department of Clinical Sciences of Companion Animals, Uirechl University, PO Box 80. 154, 3508 TD, Utrecht, the Netherlands
The effect of phenylbutazone on the plasma disposition of penicillin G in the horse
Authors: FIRTH E. C. , NOUWS J. F. M. , KLEIN W. R. , DRIESSENS F. 
Published: April 2008

Firth, E.C., Nouws, J.F.M., Klein, W.R. & Driessens, F. The effect of phenylbutazone on the plasma disposition of penicillin G in the horse. J. vet. Pharmacol. Therap. 13, 179–185.A pilot study in two ponies showed that the plasma concentrations of intramuscularly administered procaine penicillin were higher if phenylbutazone was administered concurrently. In two other trials, each involving five horses, intravenous sodium penicillin was administered with and without concurrent intravenously injected phenylbutazone, and procaine penicillin was injected intramuscularly with and without oral phenylbutazone. In both cases the plasma concentrations of penicillin were higher when phenylbutazone was given. The pharmacokinetic parameters indicated that the effect was probably due to a lower peripheral distribution because the penetration of penicillin into the tissues was greatly reduced. E. C. Firth, Veterinary Surgery and Companion Animal Health, Department of Clinical Sciences, Faculty of Veterinary Science, Massey University, Palmerston North, New Zealand.
Effects of non‐steroidal anti‐inflammatory drugs on canine neutrophil chemotaxis
Authors: STRØM H. , THOMSEN M. KROGSGAARD 
Published: April 2008

Strøm, H. & Krogsgaard Thomsen, M. Effects of non‐steroidal anti‐inflammatory drugs on canine neutrophil chemotaxis. J. vet. Pharmacol. Therap. 13, 186–191.Non‐steroidal anti‐inflammatory drugs exhibit differences in their ability to suppress polymorphonuclear leucocyte (PMN) functions in different species. The present study investigated the in‐vitro and ex‐vivo effects of phenylbutazone and flunixin on leukotriene‐B4‐directed migration of canine PMN. Furthermore, in‐vitro comparison was made to indomethacin and the 5‐lipoxygenase inhibitor, nordihydroguaiaretic acid (NDGA). In vitro, flunixin and NDGA were the most potent inhibitors, with IC50s of 13 and 7 μmol/l, respectively. Phenylbutazone had an IC50 of 42 μmol/l whereas indomethacin did not achieve 50% inhibition at concentrations less than 100 μmol/l. Ex vivo, flunixin almost completely abolished the LTB4 response at 1h, and still possessed significant inhibitory activity 24 h after a dosage of 1mg/kg i.v. Phenylbutazone was less active ex vivo but did suppress chemotaxis by 23% (P<0.05) at 1h following an i.v. dose of 20mg/kg. It is suggested that part of the anti‐inflammatory action of flunixin in dogs may be attributed to inhibition of PMN recruitment. M. Krogsgaard Thomsen, Department of Pharmacology, Leo Pharmaceutical Products, DK‐2750, Ballerup, Denmark.
Pharmacokinetics of sulfadimidine and its N4‐acetyl metabolite in healthy and diseased rabbits infected with Pasteurella multocida
Authors: YUAN ZHONG‐HUI , FUNG KI‐FAI 
Published: April 2008

Yuan, Zhong‐Hui & Fung, Ki‐Fai. Pharmacokinetics of sulfadimidine and its N4‐acetyl metabolite in healthy and diseased rabbits infected with Pasteurella multocida. J. vet. Pharmacol. Therap. 13, 192–197.The pharmacokinetics of sulfadimidine (SDM) and its N4‐acetyl metabolite (N4SDM) were investigated after intravenous bolus injection of a single dose (200mg/kg) of SDM in normal and diseased New Zealand white rabbits. The apparent distribution volume at steady state, total body clearance and elimination half‐life of SDM in normal animals were 0.7±0.3l/kg, 0.57±0.24 l/kg/h and 1.6±1.3h, respectively. Of the administered dose, 62.1% was metabolized by N4‐acetylation, and 12.7±1.1 and 2.8±1.8% of the dose was excreted as free drug by the kidney and gastrointestinal tract, respectively. The ‘apparent’ formation and elimination half‐lives of N4‐SDM were 0.6±0.4 and 2.2±1.1h, respectively. The metabolite was eliminated mainly by excretion through the kidney. There was no significant effect of acute pasteurellosis on the pharmacokinetics of either SDM or N4SDM in rabbits. Yuan Zhong‐Hui, Laboratory of Veterinary Pharmacology, Department of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
Effects of nitrofurans on adrenal cortical tissue in chickens
Authors: BARTLET A. L. , KHAN F. H. 
Published: April 2008

Bartlet, A.L. & Khan, F.H. Effects of nitrofurans on adrenal cortical tissue in chickens. J. vet. Pharmacol. Therap. 13, 206–216.In chicken adrenal glands, aspartate transaminase (AST) activity is concentrated in the adrenal cortical cells. Administration of a bolus dose of furazolidone (200mg/kg) to the birds produced a decrease in AST activity in the adrenal glands and a general disorganization in the ultrastructure of the adrenal cortical cells. Many adrenal cortical mitochondria appeared to be moribund, being swollen, without cristae or apparently empty. These effects preceded atrophy of the adrenal cortical tissue, which was most marked in the central part of the adrenal glands. The atrophy was still present after 12 weeks, and it is therefore suggested that nitrofurans may be useful in the treatment of Cushing's disease in other animal species. When furazolidone or furaltadone was given in the diet at therapeutic levels, blebs of an electron‐dense substance developed in adrenal cortical mitochondria and AST activity in the adrenal glands was reduced. These effects were found to be reversible, and the treatments did not produce atrophy of the adrenal cortical tissue. A. L. Bartlet, Department of Preclinical Veterinary Sciences, Faculty of Veterinary Medicine, University of Edinburgh, Edinburgh EH9 IQH, UK.
Contrasting effects of nitrofurans on plasma corticosterone in chickens following administration as a bolus or diet additive
Authors: BARTLET A. L. , HARVEY S. , KLANDORF H. 
Published: April 2008

Bartlet, A.L., Harvey, S. & Klandorf, H. Contrasting effects of nitrofurans on plasma corticosterone in chickens following administration as a bolus or diet additive. J. vet. Pharmacol. Tlierap. 13, 261–269.Administration of furazolidone as a bolus dose (8–500 mg/kg), produced a decrease in plasma corticosterone in chickens. In contrast, addition of furazolidone or furaltadone to the diet (0.04% or above, 10 days), increased plasma corticosterone. Pre‐treatment with a 200‐mg/kg bolus of furazolidone or furaltadone did not affect pentobarbitone anaesthesia time in the birds. In chickens pre‐treated with a nitrofuran in the diet, however, pentobarbitone anaesthesia time was significantly less than that in controls. Furaltadone in the diet, produced significant increases in the amount of cytochrome P‐450 and the activity of aniline hydroxylase in the liver microsomes. It is suggested that nitrofurans given in the diet stimulated corticosterone biosynthesis in the adrenal glands and induced mixed‐function oxidase activity in the liver. Nitrofurans given as a bolus did not produce these effects. Furazolidone (200 mg/kg) produced severe anorexia, which lasted 2 days in T‐line birds. The anorexia seemed to be associated with tissue damage in the birds rather than the ensuing adrenal cortical insufficiency. A. L. Bartlet, Department of Preclinical Veterinary Sciences, Faculty of Veterinary Medicine, University of Edinburgh, Edinburgh EH9 1QH, UK.
Tissue concentrations of clindamycin after multiple oral doses in normal cats
Authors: BROWN S. A. , ZAYA M.J. , DIERINGER T. M. , HUNTER R. P. , NAPPIER J. L. , HOFFMAN G. A. , HORNISH R. E. , YEIN F. S. 
Published: April 2008

Brown, S.A., Zaya, M.J., Dieringer, T.M., Hunter, R.P., Nappier, J.L., Hoffman, G.A., Hornish, R.E. & Yein, F.S. Tissue concentrations of clindamycin after multiple oral doses in normal cats. J. vet. Pharmacol. Therap. 13, 270–277.Eighteen normal cats were randomly allocated into two blocks with three treatment groups and dosed orally with clindamycin aqueous solution for 10 days at a dosage rate of 5.5 mg/kg twice daily (Group 1), 11 mg/kg twice daily (Group 2), or 22 mg/kg once daily (Group 3). At the end of dosing, all cats were killed and tissues were taken for clindamycin concentration analysis. Clindamycin was extracted from tissues using solid‐phase extraction columns followed by microbiological assay of clindamycin using a cylinder plate assay using M. luteus. Recovery from each tissue was determined by inoculating known concentrations of clindamycin into drug‐naive tissues and comparing the observed concentration from the expected concentration. Confirmation that the bioassay detected clindamycin and not N‐desmethylclindamycin, its active metabolite, was done using gas‐chromatography‐mass‐spectrometry. Concentrations were highest in the lung, with tissue: serum ratios greater than 3 in all groups. Concentrations were higher in Group 3 than Group 1 (P< 0.05). Only liver concentrations in Group 3 were statistically higher than in Group 2, although all tissues except bone marrow and CSF had numerically higher concentrations in Group 3 than Group 2. The tissuerserum ratio was < 1 in all tissues studied except bone, cerebrospinal fluid, brain, and skeletal muscle. Dr Scott Anthony Brown, Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine, Texas A<M University, College Station, TX 77843, USA.
Chronopharmacokinetics of theophylline in the cat
Authors: DYE J. A. , McKIERNAN B. C. , NEFF‐DAVIS C. A. , KORITZ G. D. 
Published: April 2008

Dye, J.A., McKiernan, B.C., Neff‐Davis, C.A. & Koritz, G.D. Chronopharmacokinetics of theophylline in the cat. J. vet. Pharmacol. Therap. 13, 278–286.Studies of theophylline pharmacokinetics in humans have shown that a higher peak concentration and area under the curve (AUC), with a shorter time to peak (tp) occur after a morning dose than after an evening dose. The purpose of this study was to determine whether theophylline pharmacokinetics in the cat were also influenced by the administration time of day. Theophylline was administered to six cats in a three‐way cross‐over study as a single dose of intravenous aminophylline and oral sustained‐release theophylline (Slo‐bid Gyrocapsr̀ and Theo‐Durr̀ Tablets), between 08.00–09.00 h (Phase I) and 20.00–21.00 h (Phase II). Subjects were maintained on a 12‐h light (08.00–20.00 h):12‐h dark cycle. Similar to the human studies, the tp was shorter following the morning dose. Conversely, however, the peak plasma theophylline concentrations achieved in these cats following intravenous aminophylline and oral Slo‐bidr̀ were significantly higher following the evening dose. The AUC obtained for Theo‐Durr̀ was also significantly greater following the evening dose. No single pharmacokinetic parameter could account for the higher plasma concentrations achieved following the evening dose. J. A. Dye, Department of Veterinary Clinical Medicine, University of Illinois, Urbana, IL 61801, USA.