Diabetic BioBreeding/Worcester (BB/Wor) rats need not be lymphopenic

Area of Science:

• Immunology
• Endocrinology
• Animal Models

Background:

• The BB/Wor rat is a widely used animal model for studying spontaneous autoimmune type I diabetes mellitus.
• Previous research indicated that lymphopenia (a low lymphocyte count) is a consistent feature of diabetic and diabetes-prone BB rats.

Purpose of the Study:

• To investigate the occurrence of diabetes in BB/Wor rat family lines previously free of the condition.
• To determine if lymphopenia is a mandatory characteristic for the development of diabetes in the BB/Wor rat model.

Main Methods:

• Observation of three family lines of BB/Wor rats for the spontaneous development of diabetes.
• Assessment of lymphocyte counts and phenotypic T cell subsets in newly diabetic rats.

Main Results:

• Diabetes spontaneously appeared in three previously diabetes-free family lines of BB/Wor rats.
• The newly diabetic rats (W-line) were not lymphopenic.
• These diabetic W-line rats exhibited normal percentages of phenotypic T cell subsets.

Conclusions:

• The presence of lymphopenia is not an obligatory requirement for the development of autoimmune type I diabetes in BB/Wor rats.
• These findings broaden the understanding of the pathogenesis of diabetes in this animal model.
• Further research is needed to explore alternative mechanisms contributing to diabetes in non-lymphopenic BB/Wor rats.