Insulin-like growth factor I (IGF-I) delays the onset of diabetes in non-obese diabetic (NOD) mice.
It has been shown that prophylactic exogenous insulin treatment prevents the development of insulin-dependent diabetes mellitus (IDDM) in animal models and humans. In this study, we examined whether the development of diabetes and insulitis in female non-obese diabetic (NOD) mice could be affected by prophylactic administration of insulin-like growth factor I (IGF-I), which shares structural homology with insulin and has insulin-like metabolic effects. Two experiments which differed in duration and dosage of IGF-I treatment were carried out. In the first experiment, animals were treated from 4 to 9 weeks of age with IGF-I (17.9 nmol/day at 4-5 weeks of age and 35.9 nmol/day at 6-9 weeks of age) and observed up to 34 weeks of age. In the second experiment, the animals were treated from 4 to 34 weeks of age with IGF-I (1.79 nmol/day at 4-5 weeks of age, 3.59 nmol/day at 6-9 weeks of age, and 5.38 nmol/day at 10-34 weeks of age). The former treatment could significantly delay the onset of diabetes (P < 0.05) and decrease the insulitis score at 10 weeks of age (P < 0.01). On the other hand, the latter treatment did not affect the incidence of diabetes, the age at onset or the insulitis score. Our results suggest that the IGF-I treatment at the early age may provide protection against autoimmune beta-cell destruction in NOD mice.
Kaino
Y
Y
Department of Pediatrics, Ehime University School of Medicine, Japan.
Hirai
H
H
Ito
T
T
Kida
K
K
D000375:Aging; D000704:Analysis of Variance; D000818:Animals; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics / Q000473:pathology / Q000517:prevention & control*; D005260:Female; D015994:Incidence; D007328:Insulin / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D007515:Islets of Langerhans / Q000187:drug effects / Q000473:pathology*; D051379:Mice; D016688:Mice, Inbred NOD
D001786:Blood Glucose; D007328:Insulin; D007334:Insulin-Like Growth Factor I