The effect of chilling, freezing, and rewarming on the postmortem chemistry of vitreous humor.

The effect of chilling at the time of death on the postmortem chemistry of the vitreous humor was studied by using sheep heads obtained immediately following decapitation. One group of heads was kept at room temperature, while the remainder were chilled on ice or in ice water, then refrigerated or frozen. Vitreous humor specimens were taken at intervals over a 48-h period. Chilling inhibited the fall in the glucose concentration and the total carbon dioxide content and lessened the increase in lactic acid, compared to the room temperature group. Rapid glycolysis resumed when the heads rewarmed to room temperature starting at 6-h postmortem, but did not resume at later points. The rate of rise of the potassium and magnesium concentrations was also diminished in the chilled eyes. Freezing and thawing caused an abrupt increase in the potassium and magnesium levels, but other solutes were unaffected.