The use of bone marrow in the study of postmortem redistribution of nortriptyline

Thirty-two New Zealand Albino rabbits (1.5-2.0 kg) were dosed on a daily basis with 20 mg/kg nortriptyline (NT) prior to feeding for a period of five days. On the fifth day of dosing, the animals were sacrificed approximately 1.5 h after the final dose. A comparison was made of nortriptyline concentrations in the blood and bone marrow at the time of sacrifice, and between bone marrow collected at the time of sacrifice and bone marrow collected at 2, 4, 6, 12, 24, 36, and 48 h after sacrifice. The results indicate that a linear relationship exists between blood and bone marrow NT concentrations, with an average marrow-to-blood ratio of 29.98 +/- 3.91 and a correlation coefficient of 0.956. Additionally, there was no significant difference (p > 0.05) observed between NT concentrations in bone marrow at the time of sacrifice and its concentration up to 24 h after sacrifice. The results indicate that bone marrow may be used to predict blood concentrations of NT up to 24 h after death when a suitable blood sample is not available.