Adrenal lesions in the baboon (Papio spp).

Area of Science:

• Veterinary Pathology
• Primate Histology
• Toxicology

Background:

• Adrenal gland histology is crucial for understanding physiological changes.
• Spontaneous lesions in non-human primate models can impact drug safety studies.
• Yellow (Papio cynocephalus) and olive (Papio anubis) baboons are frequently used in preclinical research.

Purpose of the Study:

• To document the prevalence and types of spontaneous lesions in baboon adrenal glands.
• To provide a baseline histological reference for drug safety evaluations.
• To identify common pathological changes in baboon adrenal glands.

Main Methods:

• Histological examination of 604 pairs of adrenal glands from yellow and olive baboons.
• Systematic recording of all observed spontaneous lesions.
• Categorization of lesions into cortical and medullary types.

Main Results:

• Spontaneous lesions were identified in 372 out of 604 (61.6%) adrenal glands.
• The most frequent cortical lesions included accessory nodules (190) and focal fatty change (60).
• Medullary lesions were less common, primarily consisting of focal lymphocytic infiltrates (66).

Conclusions:

• Spontaneous adrenal gland lesions are prevalent in yellow and olive baboons.
• Understanding these lesions is essential for interpreting findings in drug safety studies.
• Accessory nodules and focal fatty change are key histological findings to monitor in this primate model.