Effect of insulin-like growth factor I infusion on renal hypertrophy in experimental diabetes mellitus in rats.
Initial diabetic renal hypertrophy is preceded by a transient increase in kidney insulin-like growth factor I suggesting that insulin-like growth factor I may be implicated in diabetic kidney growth. The present study was undertaken to examine the effects of exogenous insulin-like growth factor I infusion on diabetic renal hypertrophy at a time when renal insulin-like growth factor I concentration had returned to normal and the initial steep kidney growth rate had diminished to a much slower rate. Groups of rats with diabetes duration of 5 days were infused s.c. for 4 subsequent days with equimolar concentrations of insulin-like growth factor I (36 nmol/day) or insulin (35 nmol/day). Insulin infusion lowered blood glucose to a normal level within 2 days and induced an average body-weight gain of 9.3 +/- 0.6 g/day. Insulin-like growth factor I infused diabetic rats maintained the original diabetic state with blood glucose levels comparable to those of 0.154 mol/l NaCl-infused diabetic rats, but had nevertheless an average body-weight gain of 6.8 +/- 1.0 g/day while untreated diabetic rats had a lower body-weight gain amounting to 3.3 +/- 0.8 g/day (p less than 0.01). The kidney weight at day 9 in untreated diabetic animals was about 25% greater than that of non-diabetic control animals, while in insulin-like growth factor I treated diabetic rats a further increase (p less than 0.05) was seen, amounting to 36% above control level. No increase was seen in the insulin-treated diabetic group.(ABSTRACT TRUNCATED AT 250 WORDS)
Flyvbjerg
A
A
Institute of Experimental Clinical Research, University of Aarhus, Denmark.
Bornfeldt
K E
KE
Orskov
H
H
Arnqvist
H J
HJ
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D003921:Diabetes Mellitus, Experimental / Q000473:pathology / Q000503:physiopathology*; D006984:Hypertrophy; D007262:Infusions, Intravenous; D007334:Insulin-Like Growth Factor I / Q000008:administration & dosage / Q000235:genetics / Q000494:pharmacology*; D007668:Kidney / Q000187:drug effects / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D051381:Rats; D011919:Rats, Inbred Strains; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000494:pharmacology
D001786:Blood Glucose; D012333:RNA, Messenger; D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I