[Functioning of the oxidizing phase of the pentosephosphate pathway in rat liver in the development of vitamin B1 deficiency in the animals].
B1-hypovitaminosis was simulated in white rats of 150-170 g body mass by means of hydroxythiamin administration at a daily dose of 4, 40 or 100 mg/kg within 10 days. Concentrations of NADP and NADPH, main cofactors of 6-phosphogluconate dehydrogenase, were dissimilarly altered in the animal liver tissue depending on the antimetabolite dose administered. Kinetic characteristics of 6-phosphogluconate dehydrogenase isozymes were shifted towards more active binding of substrates in the hypovitaminosis. Total pool of metabolites, realized via 6-phosphogluconate dehydrogenase catalytic reactions and regulated by concentration of substrates, was especially sensitive to alterations in the NADP/NADPH ratio. In severe B1-hypovitaminosis caused by hydroxythiamin the rate of oxidative reactions was increased 3-10-fold.
D000818:Animals; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D009249:NADP / Q000378:metabolism; D010084:Oxidation-Reduction; D010119:Oxythiamine / Q000494:pharmacology; D010428:Pentosephosphates / Q000378:metabolism*; D010734:Phosphogluconate Dehydrogenase / Q000378:metabolism; D051381:Rats; D013832:Thiamine Deficiency / Q000378:metabolism*
D010428:Pentosephosphates; D010119:Oxythiamine; D009249:NADP; D010734:Phosphogluconate Dehydrogenase
Funktsionirovanie okislitel'noĭ vetvi pentozofosfatnogo puti v pecheni krys pri razvitii nedostatochnosti vitamina B1 u zhivotnykh.