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Abstract

Objective—To evaluate whether immunosuppressive doses of cyclosporine (CsA) have an adverse effect on the liver, kidney, and pancreatic beta cells of pigs.

Animals—8 juvenile 8-week-old Landrace X Large White crossbred pigs.

Procedure—CsA (100 to 140 mg/kg) was administered orally to euglycemic pigs to reach whole blood trough concentrations of approximately 1500 ng/mL. To determine pancreatic beta cell function, plasma Cpeptide and insulin concentrations were measured in response to IV administration of glucose, glucagon, arginine, and oral administration of glucose. Effects on liver and kidney were determined by monitoring serum measurements of liver function and serum creatinine concentrations, respectively.

Results—Plasma concentrations of C-peptide were significantly lower in euglycemic CsA-treated pigs, compared with control pigs, following IV administration of glucose, glucagon, arginine, and oral administration of glucose. Furthermore, the glucose clearance rate was decreased in euglycemic CsA-treated pigs, compared with control pigs. Serum creatinine concentrations and 4 of 7 serum measurements of liver function were not adversely affected by CsA administration. Serum concentrations of bilirubin and albumin were significantly increased, and serum alanine aminotransferase activity was significantly decreased in CsA-treated pigs, compared with control pigs. Histologic evaluation of liver and kidney sections revealed no pathologic findings in CsA-treated or control pigs.

Conclusions and Clinical Relevance—In our study, immunosuppressive doses of CsA caused an impairment of porcine pancreatic beta cell function, but did not have toxic effects on the kidney. However, on the basis of changes in serum bilirubin and albumin concentrations and alanine aminotransferase activity, subclinical toxic effects on the liver did occur when immunosuppressive doses of CsA were administered. (Am J Vet Res 2002;63:1501–1506)

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in American Journal of Veterinary Research

Abstract

Objective—To establish a nonterminal semen collection method for use in captive Chilean rose tarantulas (Grammostola rosea) and to evaluate tools for investigating morphology and viability of spermatozoa.

Animals—7 mature male Chilean rose tarantulas.

Procedures—Each tarantula was anesthetized in a 500-mL induction chamber containing a cotton ball infused with 2 mL of isoflurane. Semen collection was performed by applying direct pressure to the palpal bulbs (sperm storage organs) located on the distal segment of the palpal limbs. Morphology of spermatozoa was examined by light microscopy and transmission and scanning electron microscopy. Propidium iodide and a fluorescent membrane-permeant nucleic acid dye were used to evaluate cell viability.

Results—Semen was collected successfully from all 7 tarantulas. Microscopic examination of semen samples revealed coenospermia (spherical capsules [mean ± SD diameter, 10.3 ± 1.6 μm] containing many nonmotile sperm cells [mean number of sperm cells/capsule, 18.5 ± 3.8]). Individual spermatozoa were characterized by a spiral-shaped cell body (mean length, 16.7 ± 1.4 μm; mean anterior diameter, 1.5 ± 0.14 μm). Each spermatozoon had no apparent flagellar structure. The fluorescent stains identified some viable sperm cells in the semen samples.

Conclusions and Clinical Relevance—The described technique allowed simple and repeatable collection of semen from Chilean rose tarantulas. Semen from this species was characterized by numerous spherical capsules containing many nonmotile spermatozoa in an apparently quiescent state. Fluorescent staining to distinguish live from dead spermatozoa appeared to be a useful tool for semen evaluation in this species.

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in American Journal of Veterinary Research

Abstract

OBJECTIVE To determine the pharmacokinetics of pergolide after IV administration to horses.

ANIMALS 8 healthy adult horses.

PROCEDURES Pergolide mesylate was administered IV at a dose of 20 μg/kg (equivalent to 15.2 μg of pergolide/kg) to each horse, and blood samples were collected over 48 hours. Pergolide concentrations in plasma were determined by means of high-performance liquid chromatography–tandem mass spectrometry, and pharmacokinetic parameters were determined on the basis of noncompartmental methods.

RESULTS After IV administration of pergolide, mean ± SD clearance, elimination half-life, and initial volume of distribution were 959 ± 492 mL/h/kg, 5.64 ± 2.36 hours, and 0.79 ± 0.32 L/kg, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE With an elimination half-life of approximately 6 hours, twice-daily dosing may be more appropriate than once-daily dosing to reduce peak-trough fluctuation in pergolide concentrations. Further pharmacodynamic and pharmacokinetic studies of pergolide and its metabolites will be necessary to determine plasma concentrations that correlate with clinical effectiveness to determine the therapeutic range for the treatment of pituitary pars intermedia dysfunction.

Full access
in American Journal of Veterinary Research