A comparison between islet transplantation and parenteral insulin in the control of diabetes and prevention of renal complications in mice

Abstract

The control of diabetes and the prevention of renal complications were studied in mice that received different treatment regimes for six months. Transplantation of syngeneic cultured fetal pancreas completely reversed streptozotocin-induced diabetes (mean FBG 5.1 ± 0.4 mmole/liter six months after transplantation, versus 5.8 ± 0.2 mmole/liter in normal mice). The mean fasting blood glucose (FBG) level of insulin-treated mice was lower than the mean FBG level of untreated diabetic mice (9.0 ± 1.2 mmole/liter versus 11.5 ± 1.3 mmole/liter, P < 0.05) but exceeded the FBG level of transplanted mice ( P < 0.001) or normal controls ( P < 0.001). There were no significant differences between the mean level of glycosylated hemoglobin (HbA 1c) of normal (4.8 ± 0.3%), transplanted (4.5 ± 0.3%), or insulin-treated mice (5.3 ± 0.4%), but the HbA 1c level in the untreated diabetic group was increased (7.0 ± 0.5%; P < 0.001). Six months after transplantation, the thickness of the glomerular capillary basement membrane (GCBM) was not different in the transplanted group and normal controls (156.4 ± 5.7 nm versus 157.3 ± 12.6 nm); the GCBM was thicker in the insulin-treated mice than in the transplanted mice (179.8 ± 4.2 nm versus 156.4 ± 5.7 nm; P < 0.02), but thinner than in untreated diabetic mice (179.8 ± 4.2 nm versus 202.2 ± 4.4 nm; P < 0.001). It is concluded that islet transplantation, in contrast to good control as judged by normalization of HbA 1c levels achieved with parenteral insulin, prevents GCBM thickening in experimental diabetes.