Abstract
We have recently reported a new diabetic strain of rat (WBN/Kob) with endo-exocrine pancreatic insufficiency. In this strain, insulin administration is usually not necessary for survival and the strain is suitable for long-term observation. In the present study, we examined the time course of urinary protein excretion, renal function and histological changes of the kidney in order to investigate the development of diabetic nephropathy.
In male diabetic rats, 24-hour urinary total protein excretion began to increase at about 10 months of age and reached 25-300mg/24hr at 13 to 24 months of age. Electrophoretic analysis revealed that the urinary protein consisted of albumin. Under the light microscope, glomeruli with segmental or global increase in mesangeal areas were noted at 17 months of age, indicating development of marked glomerulosclerosis. Electron microscopic examination, revealed that the glomerular basement membrane in diabetic rats aged 11 months was already thickened in comparison with that in the age-matched male Wistar rats. However in long-term observation, serum creatinine levels did not increased and histologically so-called nodular glomerulosclerosis was not noted.
This WBN/Kob rat is useful as an animal model of diabetic nephropathy.
