Postmortem functional changes in coronary and cerebral arteries from humans and monkeys

Area of Science:

• Physiology
• Pharmacology
• Postmortem Biology

Background:

• Understanding postmortem changes in vascular reactivity is crucial for organ transplantation and forensic science.
• Previous studies have yielded conflicting results regarding the duration of vascular tissue viability after death.

Purpose of the Study:

• To investigate the time-dependent changes in contractile responses of human and monkey coronary and cerebral arteries after death.
• To assess the viability of vascular smooth muscle and endothelial function in postmortem arteries.

Main Methods:

• Helical strips of human and monkey coronary and cerebral arteries were isolated at various postmortem intervals.
• Contractile responses to potassium chloride (KCl), acetylcholine, noradrenaline, histamine, and serotonin were measured.
• The role of the endothelium in mediating responses was examined.

Main Results:

• Potassium-induced contractions in human coronary arteries were maintained for up to 5 hours postmortem, then suppressed at 8 hours.
• Monkey coronary arteries showed similar K+-induced contraction stability for 5 hours, with suppression at 12 hours.
• Human and monkey cerebral arteries retained K+-induced contractions for 20-24 and 8-16 hours, respectively.
• Acetylcholine induced contractions in human coronaries and relaxation in monkey coronaries (endothelium-dependent).
• Noradrenaline, histamine, and serotonin induced sustained contractions in human coronary arteries for 3-5 hours, and noradrenaline in cerebral arteries up to 20 hours.

Conclusions:

• Human coronary artery reactivity to K+ and vasoconstrictors is retained for at least 6 hours postmortem.
• Human cerebral artery reactivity is maintained for up to 24 hours postmortem.
• Vascular smooth muscle in cerebral arteries exhibits greater postmortem stability compared to coronary arteries.