BRIEL, G., E. GYLFE, B. HELLMAN and V. NEUHOFF. Microdetermination of free amino acids in pancreatic islets isolated from obese-hyperglycemic mice. Acta physiol. scand. 1972. 84. 247-253.Free amino acids were measured with a microtechnique employing labelling with fGdansy1-C1 and separation with two-dimensional thin-layer chromatography. Most amino acids occurred in greater amounts in the islets than in the exocrine pancreas. Aspartic acid, valine and leucine were present in tenfold amounts. I t is postulated that the ,!l-cells are equipped with binding sites for large amounts of the latter amino acid. Like nervous tissue, the pancreatic islets were characterized by the presence of gamma-aminobutyric acid and high levels of taurine.

Microchromatography on 3 x 3 cm polyamide layers of dansyl-compounds was used to study the distribution of free amino acids, GABA, serotonin, 5-hydroxyindole and 5-hydroxytryptophan in the brain, optic tentacle, pharyngeal retractor muscle and heart of Helix pomuriu. In addition the formation of GABA after incubation in U-I r C glucose or U-*rC glutamic acid was studied.Low amounts of GABA were for the first time shown to occur in all four tissues studied. In addition taurine, thought to be absent from terrestrial gastropods, was shown to occur in the snail's tissues.I n cirro incubation of brain and heart with 1% labelled glucose demonstrated the formation of 1% glutamic acid, 14C glutamine, 1 * c alanine and 1% aspartic acid. These amino acids, in addition to *4C GABA, were formed when brain and heart were incubated with 1-labelled glutamic acid. The distribution of amino acids in all other tissues studied showed some similarities, with the exception of ornithine which is low in the brain compared with the high amounts in tfre heart, pharynseal retractor mwcle and optic tentacle. The brain differs also from the other tissues studied in having a higher concentration of glycine, glutamic acid, serotonin and 5-hydroxytryptophan. Furthermore. 5-hydroxyindole was only found in the brain.

No abstract

No abstract

No abstract