Growth restoration of insulin-deficient diabetic rats by recombinant human insulin-like growth factor I.
Insulin-like growth factor I (IGF-I) and insulin stem from a common precursor, are structural homologues, act through similar receptors and elicit insulin-like and growth-promoting effects in vitro and in vivo. Serum IGF-I levels are controlled by growth hormone, insulin and nutrition. Insulin-deficient growth-arrested diabetic animals have reduced serum IGF-I levels which are restored towards normal by insulin but not by growth-hormone treatment. Here we show that normal growth of diabetic rate is restored by infusion of recombinant human (rh)IGF-I without normalization of the blood sugar level and that insulin acts via an increase of IGF-I synthesis on growth of diabetic rats. We describe a new mechanism of endocrine control of growth in which IGF-I is the major stimulator at the cellular level. Growth hormone and insulin act mainly by modulating the hepatic synthesis of IGF-I.
D000818:Animals; D001786:Blood Glucose; D003921:Diabetes Mellitus, Experimental / Q000150:complications*; D006128:Growth / Q000187:drug effects; D006130:Growth Disorders / Q000209:etiology / Q000628:therapy*; D013006:Growth Hormone / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000627:therapeutic use*; D008297:Male; D051381:Rats; D011994:Recombinant Proteins / Q000627:therapeutic use*; D013002:Somatomedins / Q000627:therapeutic use*
D001786:Blood Glucose; D007328:Insulin; D011994:Recombinant Proteins; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone