Spontaneous renal lesions in five rat strains

Area of Science:

• Comparative pathology
• Toxicology and carcinogenesis research

Background:

• Rodent models are crucial for preclinical research.
• Understanding strain-specific pathologies is vital for study design.

Purpose of the Study:

• To survey and compare non-neoplastic and neoplastic renal lesions in five rat strains.
• To identify suitable rat strains for long-term toxicology and carcinogenesis studies.

Main Methods:

• Histopathological examination of renal tissues from five rat strains: ACI, A22807, F344, M520, and OM.
• Analysis of lesion incidence, spectrum, and severity.

Main Results:

• Osborne-Mendel rats exhibited high incidences of renovascular lesions.
• Marshall and ACI rats showed extensive calculus formation and associated lesions.
• ACI rats also presented with a notable incidence of congenital renal agenesis.
• A28807 and F344 strains had less severe chronic renal disease, but A28807 had higher pelvic transitional cell hyperplasia.

Conclusions:

• Osborne-Mendel, Marshall, and ACI rat strains possess significant disadvantages for long-term studies due to prevalent renal lesions.
• The A28807 and F344 strains present a more complex choice, requiring consideration of extra-renal lesions for optimal selection.
• Strain selection for long-term studies must balance renal lesion profiles with extra-renal pathologies.