In the submitted review the author discusses two substances secreted into the circulation which can similarly as insulin lower the blood sugar level. These substances are IGF-I (insulin-like growth factor I) and GLP (glucagon-like peptide). While in case of the former it is not certain whether it participates in the glucose homeostasis, this is beyond doubt in the latter. IGF-I prepared by the recombinant technique can be used therapeutically in cases of insulin resistance caused by a receptor or postreceptor disorder, because it may act via its own receptor. Side-effects after larger doses are a problem. GLP-1, the use of which would be useful in type 2 diabetics as it stimulates insulin secretion, is not used so far in therapy because hitherto prepared preparations have a very short period of a effectiveness.

Keywords: Blood Glucose /metabolism/; Glucagon /adverse effects/; Glucagon-Like Peptide 1; Humans; Insulin Resistance; Insulin-Like Growth Factor I /adverse effects/; Pancreatic Hormones /physiology/; Peptide Fragments /adverse effects/; Peptides /adverse effects/; Protein Precursors /adverse effects/