Pharmacokinetics of paracetamol in the Thoroughbred horse following an oral multi-dose administration.

Paracetamol is a widely used, non-opioid analgesic and antipyretic drug. Scientific evidence suggests that it is an effective pain treatment in equine medicine. However, there is very little published information about the pharmacokinetics of the drug in the horse. The aim of the research was to determine the pharmacokinetics of paracetamol in equine plasma and urine to inform treatment of Thoroughbred racehorses. In this multi-dose study, paracetamol was administered orally at 20 mg/kg to six Thoroughbred horses. Pre- and post-administration urine and plasma samples were collected and analysed using a quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Pharmacokinetic analysis of urine and plasma paracetamol clearance profiles was carried out, which enabled the calculation of possible screening limits (SL) that can regulate for a detection time of 120 h. Additionally, an estimation of orthocetamol concentration levels in urine was carried out to investigate any underlying relationship between the para- and ortho-isomers as both were suspected to contribute to basal levels, possibly due to environmental feed sources.

Detection of adeno-associated viral DNA in equine post-administration frozen blood and plasma samples after long-term storage.

Gene doping in horses is a threat to the fairness in sport and has serious implications for animal welfare. To investigate the effect of long-term storage on the detection of AAV in plasma and whole blood, samples from an administration study using an adeno-associated virus serotype 6 expressing green fluorescence protein (AAV6-GFP) were stored at -20°C for 8 months before analysis. The AAV vector was detected in stored plasma samples, following the same detection profile as the fresh plasma samples. The stored blood showed lower overall DNA detection but followed the same detection profile as the plasma samples. This study provides confidence that re-analysing plasma samples and/or analysing a frozen 'B' sample with different matrix such as whole blood after prolonged storage will still result in the detection of gene doping material.

Postmortomics: The Potential of Untargeted Metabolomics to Highlight Markers for Time Since Death.

The success of forensic investigations involving fatalities very often depends on the establishment of the correct timeline of events. Currently used methods for estimating the postmortem interval (PMI) are mostly dependent on the professional and tacit experience of the investigator, and often with poor reliability in the absence of robust biological markers. The aim of this study was to investigate the potential of metabolomic approaches to highlight molecular markers for PMI. Rat and human muscle tissues, collected at various times postmortem, were analyzed using an untargeted metabolomics approach. Levels of certain metabolites (skatole, xanthine, n-acetylneuraminate, 1-methylnicotinamide, choline phosphate, and uracil) as well as most proteinogenic amino acids increased steadily postmortem. Threonine, tyrosine, and lysine show the most predictable evolution over the postmortem period, and may thus have potential for possible PMI markers in the future. This study demonstrates how a biomarker discovery approach can be extended to forensic investigations using untargeted metabolomics.