Postmortem time and storage temperature affect the concentrations of hypoxanthine, other purines, pyrimidines, and nucleosides in avian and porcine vitreous humor.

An HPLC method was used to determine whether postmortem time and storage temperature affect the concentrations of purines, pyrimidines, and nucleosides in avian and porcine vitreous humor. Inosine, hypoxanthine, xanthine, uric acid, uracil, uridine, and thymine were identified in the vitreous humor of chickens (Gallus domesticus). Time from death to sample collection (0-192 h) influenced the concentrations of all seven compounds (p less than 0.01 to less than 0.0001). The storage temperature of chicken carcasses before sampling (6 or 20 degrees C) had a significant influence on the concentrations of inosine, hypoxanthine, xanthine, uric acid, uracil, and thymine (p less than 0.05 to less than 0.0001). The interaction of postmortem time with temperature was significant for all seven compounds (p less than 0.01), with the rate of increase in concentration over time being higher at 20 than 6 degrees C. At 0 h postmortem, the vitreous humor of pigs (Sus scrofa) contained detectable levels of hypoxanthine, uracil, and uridine. Inosine, hypoxanthine, xanthine, guanosine, guanine, uracil, and uridine were detected after storage of pig eyes for 24 h at 20 degrees C. Between 0 and 24 h postmortem, there was a 22-fold increase in hypoxanthine concentration and a 13-fold increase in uracil concentration (p less than 0.0001). It was concluded that postmortem time and temperature are factors that must be taken into consideration when making comparisons of purines, pyrimidines, and nucleosides between groups and in relating postmortem vitreous humor hypoxanthine concentrations to antemortem hypoxia.