Effects of recombinant insulin-like growth factor I on insulin secretion and renal function in normal human subjects.
Insulin-like growth factor I (IGF-I) is an important mediator of growth hormone (GH) action and it appeared tempting to evaluate possible clinical applications. Recombinant IGF-I was infused s.c. at a dose of 20 micrograms/kg of body weight per hour during 6 days in two healthy adult subjects. Blood glucose and fasting insulin levels remained within normal limits and IGF-II levels were suppressed. In contrast to insulin, fasting C peptide levels were decreased. GH secretion was also suppressed by IGF-I. Our preliminary data allow us to distinguish between the effects of GH per se and those of IGF-I: GH causes hyperinsulinism, whereas IGF-I leads to decreased insulin secretion. Glomerular filtration rate, as estimated by creatinine clearance, increased to 130% of preinfusion values during the IGF-I infusion. Total creatinine and urea excretion remained unchanged. We conclude that IGF-I influences kidney function and, in contrast to GH, exerts an insulin-sparing effect. It may be speculated that the therapeutic spectrum of IGF-I is quite different from that of GH.
Guler
H P
HP
Department of Medicine, University Hospital, Zürich, Switzerland.
Schmid
C
C
Zapf
J
J
Froesch
E R
ER
D000328:Adult; D002096:C-Peptide / Q000097:blood; D003404:Creatinine / Q000097:blood; D005919:Glomerular Filtration Rate / Q000187:drug effects; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007334:Insulin-Like Growth Factor I / Q000097:blood / Q000494:pharmacology*; D007335:Insulin-Like Growth Factor II / Q000097:blood; D007668:Kidney / Q000187:drug effects* / Q000502:physiology; D008297:Male; D012636:Secretory Rate / Q000187:drug effects; D013002:Somatomedins / Q000494:pharmacology*; D014508:Urea / Q000097:blood
D002096:C-Peptide; D007328:Insulin; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D014508:Urea; D013006:Growth Hormone; D003404:Creatinine