AJP - Endocrinology and Metabolism, Vol 272, Issue 5 E918-E924, Copyright © 1997 by American Physiological Society
Effect of GH/IGF-I deficiency on long-term renal changes and urinary albumin excretion in diabetic dwarf rats
H. Gronbaek, P. Volmers, S. F. Bjorn, R. Osterby, H. Orskov and A. Flyvbjerg
Electron Microscopical Diabetes Research Laboratory, University Institute of Pathology, Aarhus Kommunehospital, Denmark.
Growth hormone (GH) and insulin-like growth factor I (IGF-I) may play a
role in early diabetic renal and glomerular growth and in the later
development of experimental diabetic kidney disease. Rats from a genetic
GH/IGF-I-deficient dwarf rat strain were made streptozotocin diabetic and
were compared with nondiabetic dwarf rats. GH/IGF-I-intact rats with and
without diabetes served as controls. After 6 mo of diabetes, kidney weight
and total glomerular volume increased significantly in GH/IGF-I-intact
diabetic rats compared with the nondiabetic GH/IGF-I-intact rats (P <
0.05), whereas the diabetic dwarf rats had insignificant changes compared
with dwarf control rats. By the end of the study, urinary albumin excretion
(UAE) increased from similar base levels of approximately 15-20
micrograms/24 h to 473 +/- 52 (SE) micrograms/24 h in GH/IGF-I-intact
diabetic rats compared with 151 +/- 32 micrograms/24 h in diabetic dwarf
rats (P < 0.01). In conclusion, isolated GH/IGF-I deficiency reduces the
degree of renal and glomerular hypertrophy and the increase in UAE after 6
mo of experimental diabetes in GH/IGF-I-deficient rats.
