Electrophysiology and pathology evaluation of the Yucatan pig as a non-rodent animal model for regulatory and mechanistic toxicology studies

Abstract

SummarySix male and six female Yucatan pigs were utilized to investigate the feasibility of this species as a non-rodent model for routine regulatory and mechanistic toxicology studies. This study evaluated disease surveillance and computerized electrophysiology, along with possible gross and micropathology changes. Two pigs were used as sentinel animals to evaluate the microbiological status of the vendor upon arrivalj the other pigs were maintained as biomonitors and to provide baseline clinical chemistry, urinalysis, pathology and electrophysiology data. The electrophysiology tests conducted included electrocardiography (ECG), electroretinography (ERG) and quantitative electroencephalography IqEEG), which achieved consistent baseline values with acceptable intrasubject variation. Tissue cholinesterase and histochemical staining were done to determine their suitability for testing cholinesterase compounds. Evaluation of the serum chemistry profile demonstrated increased CPK and LDH, which was likely associated with slight haemolysis or minor subclinical muscle stress during handling. There were no additional clinical chemistry changes or findings in haematology, urinalysis parameters or gross pathology. Micropathology found an absence of background lesions which would interfere with routine toxicology studies, except for a mild rhinitis. The aetiological agent was identified by electron microscopy as being consistent with inclusion body rhinitis of swine, previously unreported in miniature swine. This would most notably interfere with inhalation studies. The anatomical and physiological similarities of the Yucatan pig, .along with its ability to accept the performance of electrophysiology tests allow this species to be considered as a suitable model for organ system testing in toxicology studies. Keywords Electrophysiology; cholinesterasej inclusion body rhinitis; Yucatan pigThe complexities of biotransformation, physiology, and pharmacogenetics cause scientists to consider the most appropriate animal models for human extrapolation when conducting the safety testing of drugs and chemicals (Lloyd 1986). The Yucatan pig, Yucatan micropig, G6ttingen miniature swine and others have been extensively used Correspondence to: R. D. fones as animal research models in the areas of cardiovascular disease, atherosclerosis, cerebrovascular disease, gastric ulcers, alcoholism, stress physiology, obesity, dermatology, porphyria and immunotoxicology (Pond 1978, Rispat et al. 1993. The purpose of this study was to expand the database on the Yucatan pig as an appropriate toxicological and pharmacological model for safety testing

Normative Data of Axial Length, Retinal Thickness Measurements, Visual Evoked Potentials, and Full-Field Electroretinography in Female, Wild-Type Minipigs

“…Previous studies of ERG using normal pig showed the a-wave implicit time (16.6 ms) in rod-cone response, b-wave implicit time (41.8–47.4 ms) in rod-cone response, a-wave implicit time (12.7–16.7 ms) in maximal rod-cone response, b-wave implicit time (36.0–45.0 ms) in maximal rod-cone response, a-wave implicit time (8.37–13.4 ms) in cone response, and b-wave implicit time (29.6–33.5 ms) in cone response. 33 , 34 , 59 , 60 The b-wave amplitude of 10.0 ERG in our study showed a smaller amplitude than that of 3.0 ERG.…”

“Have You Seen This?”

“…Based upon the incidence patterns of this observed change, lesions were deemed to be spontaneous and, therefore, should not be considered a proliferative effect of treatment when identi ed histopathologically. Similar hepatocellular lesions have not been described in the limited published information regarding histopathologic characterization of spontaneous lesions in Yucatan minipigs (1,4) nor have they been reported in other strains of pigs.…”

The Pulmonary Veins of the Pig as an Anatomical Model for the Development of a New Treatment for Atrial Fibrillation

“…To perform research into possible treatments for atrial fibrillation in humans, a suitable animal model is needed. The porcine model has multiple times been proven to be a good animal model for humans because of comparable body size and numerous anatomical, immunological, biochemical, physiological and genetic similarities between pigs and humans (Gregg et al., ; Shulman et al., ; Delange et al., ; Bermejo et al., ; Rowan et al., ; Jones et al., ; Paterson et al., ; Sommerer et al., ; Perry et al., ; Barker et al., ; Brunet et al., ; Ibrahim et al., ; Glenny et al., ; Hotchkiss et al., ; Wang et al., ; Rogers et al., ; Khatri et al., ). The porcine heart, of which the microanatomy is representative for the mammalian heart, has an average weight of approximately 300 g, which is similar to the average weight of the human heart (approximately 300 g in men and 250 g in women) (Barone, ).…”