Impaired renal function in diabetic chimpanzees (Pan troglodytes)

Area of Science:

• Primate research
• Comparative medicine
• Endocrinology

Background:

• Two nonobese, adult female chimpanzees were identified with non-insulin-dependent impaired glucose tolerance, analogous to human Type II diabetes.
• Both animals exhibited proteinuria and glycosuria following glucose or tolbutamide administration.
• Chimpanzee 333 presented with fasting proteinuria and chronic hypertension, while chimpanzee 1037 did not.

Purpose of the Study:

• To evaluate the renal functional status in two chimpanzees with newly diagnosed non-insulin-dependent diabetes.
• To compare renal function parameters between the two diabetic chimpanzees.
• To investigate potential parallels between diabetic nephropathy in chimpanzees and humans.

Main Methods:

• Renal function was assessed using the inulin clearance method.
• Glomerular filtration rates (GFR) and electrolyte excretion rates (sodium, chloride, potassium) were measured.
• Serum biochemical parameters were analyzed for abnormalities.

Main Results:

• Both chimpanzees demonstrated significantly decreased GFR and elevated sodium excretion rates.
• Chimpanzee 1037 showed elevated chloride excretion, but potassium excretion was unaffected in both.
• Chimpanzee 333 had abnormal elevations in serum calcium, magnesium, creatinine, urea nitrogen, and uric acid; chimpanzee 1037 had only elevated creatinine.

Conclusions:

• The observed renal functional impairments in diabetic chimpanzees resemble human diabetic nephropathy.
• Differences in the severity of renal disease may correlate with the duration and severity of impaired glucose tolerance.
• A progressive course for both the diabetic and renal disorders is anticipated in these chimpanzees.