Effects of 3, &3', 5-Triiodo-L-thryonine Administration on the Embden-Meyerhof Pathway in the Kidney Cortex of the Rat.

The amount of lactate and pyruvate production by kidney cortex homogenates (cell sap and microsomal fraction) from all intermediates of the glycolytic pathway has been investigated in normal and 3,3′,5-triiodo-L-thyronine-treated rats. In normal animals the lactate and pyruvate production increases steadily from glucose (154 nmoles × mg protein-1 × h-1) through phosphoenolpyruvate (31.850 nmoles × mg protein-1 h-1). The addition in vitro of triiodo-L-thyronine to kidney cortex homogenates has no significant effect on lactate production. In the animals treated for 5 days with 1 mg/kg body weight and per diem of triiodo-L-thyronine, the lactate and pyruvate formation from various intermediates of the Embden-Meyerhof pathway is significantly (P < 0.01) increased: from glucose 225% of the control value, from glucose 6-phosphate and fructose 6-phosphate, 192%, from fructose 1,6-bisphosphate and glyceraldehyde 3-phosphate, 132%, and from 3-phosphoglycerate and 2-phosphoglycerate, 120%. No significant increase in lactate and pyruvate production has been observed using either phosphoenolpyruvate or pyruvate as substrates. [ABSTRACT FROM AUTHOR]