title: Substrate utilization by Rana ridibunda erythrocytes.
abstract: Various monosaccharides, including ribose, mannose, galactose, and urea, in combination with glucose, were studied to determine their efficacy in supporting the formation of pyruvate, lactate, 2,3-diphosphoglycerate and ATP in Rana ridibunda erythrocytes. Lactate formation was found to increase during the course of incubation in the presence of all the substrates. None of the studied substrates maintained cellular ATP levels. About 0.36 mumole of lactic acid per hour was produced for each mumol of ribose that was metabolized. The presence of 1 mM Na-iodoacetate accelerated the loss of ATP and lactate in the presence of either glucose or ribose. Additionally, ouabain suppressed lactate formation from ribose alone, as well as in combination with glucose. From the metabolic substrates studied, ribose was shown to be the most efficient substrate to support Rana ridibunda erythrocyte metabolism. Mannose, galactose and urea may also be used as alternative metabolic substrates by Rana ridibunda erythrocytes.
authors.affiliation: Zoology Department, Science School, Aristotle University of Thessaloniki, Greece.
authors.forename: M
authors.initials: M
authors.lastname: Kaloyianni
authors.forename: K
authors.initials: K
authors.lastname: Moutou
mesh_terms: D019794:2,3-Diphosphoglycerate; D000255:Adenosine Triphosphate / Q000032:analysis; D000818:Animals; D004163:Diphosphoglyceric Acids / Q000032:analysis; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D007461:Iodoacetates / Q000494:pharmacology; D019807:Iodoacetic Acid; D007773:Lactates / Q000032:analysis; D019344:Lactic Acid; D009005:Monosaccharides / Q000494:pharmacology; D010042:Ouabain / Q000494:pharmacology; D011773:Pyruvates / Q000032:analysis; D019289:Pyruvic Acid; D011895:Rana ridibunda / Q000097:blood / Q000378:metabolism*
chemical_list: D004163:Diphosphoglyceric Acids; D007461:Iodoacetates; D007773:Lactates; D009005:Monosaccharides; D011773:Pyruvates; D019794:2,3-Diphosphoglycerate; D019344:Lactic Acid; D010042:Ouabain; D019289:Pyruvic Acid; D000255:Adenosine Triphosphate; D019807:Iodoacetic Acid