The insulinotropic action of gastric inhibitory polypeptide.

The effect of highly purified gastric inhibitory polypeptide (GIP) on immunoreactive insulin (IRI) secretion in the conscious fasted dog was investigated. Significant increases in IRI release were observed with intravenous administration of three different doses of GIP. These were accompanied by depression in fasting serum-glucose levels. Preliminary studies were undertaken to determine whether this insulinotropic action of GIP could be attributed to a particular segment of the GIP molecule. GIP fragments produced by cleavage with cyanogen bromide and trypsin showed no significant stimulation of IRI release. The possibility that GIP might itself enhance glucose uptake or potentiate insulin-induced glucose uptake was studied with the rat hemidiaphragm preparation. No such effect was observed. In the light of this and other recent work, it is concluded that GIP is a strong candidate for an active principle in the enteroinsular axis.     

Synthesis of oligonucleotides on cellulose. Part II: Design and synthetic strategy to the synthesis of 22 oligodeoxynucleotides coding for gastric inhibitory polypeptide (GIP)

A solid-phase approach using trinucleotide building blocks and functionalized cellulose as solid support was used to synthesize the 22 oligodeoxynucleotides that constitute a totally synthetic gene coding for a 43 amino acid peptide. Gastric inhibitory Polypeptide. The overall strategy used for the design and synthesis of the oligomers is described.     

Electronimmunocytochemical evidence for the K cell localization of gastric inhibitory polypeptide (GIP) in man.

Application of the semithin-thin section technique indicates that the previously proposed identification of the ultrastructurally-defined K cell with the immunocytochemically-defined GIP cell is essentially correct. The K cell is established as a distinct entity and the way is open for an explanation of its role in the physiology and pathology of the gastroenteropancreatic system.