Transplantation of adipose tissue protects BB/OK rats from type 1 diabetes development

B(io) B(reedding)/O(ttawa) K(alsburg) rats spontaneously develop insulin-dependent type 1 diabetes. Days before BB/OK rats become diabetic, their body seems to be flabby which may be attributed to loss of subcutaneous fat. However, the rats are normoglycemic and manifest 3-4 days later. This observation prompted us to search for possibilities to avoid the loss of adipose tissue. BB/OK rats were subcutaneously grafted with visceral adipose tissue. In total, 34 (71%) out of 48 male and 23 (49%) out of 47 female BB/OK rats grafted with adipose tissue developed type 1 diabetes so that significantly more females than males were protected from diabetes development (p=0.03). In the control group, 17 (85%) out of 20 male and 20 (95%) out of 21 female BB/OK rats were diabetic. Adipose tissue transplantation can protect BB/OK rats from type 1 diabetes development in a sex specific manner. One could conclude that the manipulations have influenced fat accumulation and/or fat metabolism which prevent type 1 diabetes development in about 50% of BB/OK rats. This idea is supported by the finding that a mutation in the leptin receptor of NOD mice suppresses type 1 diabetes progression.