Relationship of mammalian erythrocyte enzymes and their intermediary compounds among selected animals

Abstract

As there are few comparative studies on mammalian red cell metabolism, it was decided to study the glycolytic enzyme activities as well as related ones, and the metabolites adenosine-5´-triphosphate (ATP) and 2,3-bisphosphoglycerate (2,3-BPG). Mammalia representatives from Primates, Rodentia, Carnivora, Lagomorpha, Artyodactyla, Didelphimorphia and Xenarthra orders, obtained from Fundação Parque Zoológico de São Paulo and Centro de Bioterismo da Faculdade de Medicina da USP, were studied. The blood was collected in EDTA and ACD, the red cells were washed in saline at 4º C, lysed 1:20 in hemolysing solution by freeze-and-thaw, and the following enzymes were assayed according to standard procedures: hexokinase, glucose-6-phosphate isomerase, phosphofructokinase, aldolase, triose phosphate isomerase, glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate kinase, monophosphoglycerate mutase, enolase, pyruvate kinase, lactate dehydrogenase, as well as 2,3-bisphosphoglycerate mutase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase activities at 37ºC , and adenosine-5´-triphosphate and 2,3-bisphophoglycerate concentrations. A remarkable variation among the studied species was observed. However, it was detected a significant positive correlation between the adenosine-5´-triphosphate concentrations and triose phosphate isomerase and 2,3-bisphosphoglycerate mutase activities, as well as significant positive correlation between 2,3-bisphosphoglycerate concentration and 2,3-bisphosphoglycerate mutase activity in all studied species as a whole. Most of studied species exhibited a steady ATP concentration range between 4 and 6 µ moles.g Hb -1 except the Artiodactyla (Cervus elaphus) and Carnivora (Panthera leo, Leopardus pardalis, Canis Lupus and Chrysocyon brachyurus,) which presented values between 2 and 3 µ moles g Hb -1. However, the 2,3-BPG concentration showed remarkable variation among the studied species and among the orders.