Table 1.
Effects of prolonged refrigeration and freezing on biochemical analytes in rat serum
| Mean ± SE, day 0 | Mean (n = 9 or 10) percentage change from day 0 value |
|||
| Analyte | Refrigeration, day 7 | Frost-free −20°C freezer, day 360 | Freezing −70°C, day 360 | |
| Glucose, mg/dL | 153.3 ± 7.0 | 1.6 | (5.8) | 1.3 |
| Blood urea nitrogen, mg/dL | 21.25 ± 0.67 | 0.2 | 6.5 | (0.3) |
| Sodium, mmol/L | 145.8 ± 0.5 | (1.0) | 1.3 | 1.1 |
| Potassium, mmol/L | 5.61 ± 0.07 | (0.7) | (1.2) | 1.2 |
| Chloride, mmol/L | 97.8 ± 0.5 | (0.2) | 3.3 | 2.4 |
| Carbon dioxide, mmol/L | 32.5 ± 0.07 | (9.4)a | (31.1)a | 4.3 |
| Amylase, U/L | 1243.0 ± 37.6 | 1.4 | 0.9 | (0.6) |
| Lipase, U/L | 91.5 ± 2.7 | (0.9) | (19.1)a | 4.4 |
| Calcium, mg/dL | 11.03 ± 0.08 | 0.8 | 17.0a | 3.0 |
| Phosphorus, mg/dL | 8.64 ± 0.15 | (0.5) | 6.8 | 1.4 |
| Total protein, g/dL | 6.35 ± 0.04 | (4.1) | (2.4) | 0.5 |
| Albumin, g/dL | 3.70 ± 0.04 | (2.7) | 6.8 | (1.9) |
| Aspartate transaminase, U/L | 111.9 ± 3.5 | (3.8) | (7.1) | 8.8 |
| Alanine transaminase, U/L | 92.6 ± 1.6 | 0.4 | (54.0)a | (3.6) |
| Lactate dehydrogenase, U/L | 887.0 ± 54.2 | (8.0)a | 2.8 | 3.3 |
| Creatine kinase, U/L | 178.1 ± 19.2 | (11.1)a | (59.3)a | (2.7) |
| Alkaline phosphatase, U/L | 208.9 ± 13.2 | (2.5) | (22.9)a | 5.7 |
Values in parentheses indicate decreases from day 0 value.
a
Values are significantly (P < 0.05) different from day 0 value.