Trioses and related substances: tools for the study of pancreatic beta-cell function.
Trioses, such as D-glyceraldehyde, have been used extensively for the study of stimulus-secretion coupling mechanisms in pancreatic beta-cells. It is generally assumed that trioses enter the glycolytic pathway at the triose phosphate level, and stimulate insulin release in a manner analogous to glucose. This review focuses on a number of triose effects that are not entirely consistent with this model. These effects are likely to result, at least in part, from the actions of alpha-ketoaldehydes. One such compound, methylglyoxal, appears to be a major contaminant of triose preparations, and exerts effects on the beta-cell identical to some of those evoked by glyceraldehyde. A related substance, hydroxypyruvaldehyde, is a product of triose autoxidation, which could exert similar effects. Study of the actions of trioses and alpha-ketoaldehydes could assist our understanding of cellular physiology, in general, and beta-cell function, in particular. These substances are also likely to be of pathophysiological importance, especially in the context of sugar toxicity and autoxidative cell damage.
Department of Medicine, University of Manchester, England, UK. lbest@fs1.scg.man.ac.uk
L
L
Best
P J
PJ
Thornalley
D000818:Animals; D002478:Cells, Cultured; D005985:Glyceraldehyde / Q000494:pharmacology; D006019:Glycolysis; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects* / Q000378:metabolism; D007791:Lactoylglutathione Lyase / Q000378:metabolism; D010084:Oxidation-Reduction; D011765:Pyruvaldehyde / Q000378:metabolism / Q000494:pharmacology; D014306:Trioses / Q000494:pharmacology*
D007328:Insulin; D014306:Trioses; D005985:Glyceraldehyde; D011765:Pyruvaldehyde; D007791:Lactoylglutathione Lyase