In vivo operation of the pentose phosphate pathway in frog oocytes is limited by NADP+ availability

FEBS Letters

Guixé, Victoria¹  Ureta, Tito¹  Preller, Ana¹ 

[1] Departamento de Biologı́a, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile

关键词: Glucose metabolism;    Pentose-phosphate pathway;    NADP+;    Frog oocyte;   

DOI  :  10.1016/S0014-5793(99)00192-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Evolution of CO₂ from labelled glucose microinjected into frog oocytes in vivo may be ascribed to the pentose-P pathway, as measured by radioactive CO₂ production from [1-¹⁴C] and [6-¹⁴C]glucose. Coinjection of NADP⁺ and [¹⁴C]glucose significantly stimulated ¹⁴CO₂ production. The effect depends on the amount of NADP⁺ injected, half maximal stimulation being obtained at 0.13 mM. The increase in CO₂ production was also observed with microinjected glucose-1-P, glucose-6-P or fructose-6-P used as substrates. Phenazine methosulfate, mimicked the effects of NADP⁺. A high NADPH/NADP⁺ ratio of 4.3 was found in the cells, the intracellular concentration of NADP⁺ being 19 μM.

【 授权许可】

Unknown