Use of post mortem and in vitro tissue specimens for X-ray microanalysis

Area of Science:

• Biochemistry
• Cell Biology
• Physiology

Background:

• Understanding cellular ion distribution is crucial for interpreting experimental results.
• Post-mortem changes can significantly alter tissue composition.
• Tissue preparation methods like dissection and incubation can induce artifactual ionic shifts.

Purpose of the Study:

• To investigate post-mortem elemental distribution changes.
• To analyze ionic alterations in tissue slices due to dissection and incubation.
• To compare in vitro and in situ physiological ion changes.

Main Methods:

• X-ray microanalysis of brain, liver, pancreas, and submandibular gland tissue.
• Investigation of ionic changes after dissection and incubation in physiological buffers.
• Assessment of effects of temperature and ionic composition of incubation media.

Main Results:

• Dissection causes minor intracellular ionic shifts; brief buffer exposure increases Na+ and Cl-, decreasing K+.
• Brain tissue shows the most pronounced ionic changes, while submandibular gland is least affected.
• Incubation stabilizes ionic content in pancreas and submandibular gland but not in brain or liver.
• Lower temperatures and Na gluconate have minor effects; K gluconate maintains high K+/Na+ ratio but causes edema.
• In vitro cholinergic stimulation mimics in situ effects.

Conclusions:

• Dissection and incubation significantly alter ionic composition, especially in brain tissue.
• Post-mortem changes precede and influence the effects of tissue preparation.
• Careful consideration of preparation methods and post-mortem intervals is essential for accurate ionic analysis.