Liver and kidney cortex gluconeogenesis from L-alanine in fed and starved rats.

Abstract

I. Circulating [14C]glucose 2, 5 and 10 min after intravenous injection of [U- 14C]-L-alanine w~s greater in 24 hr starved than in fed rats. 2. In vitro uptake of [14C]alanine by liver and kidney cortex slices from 24 hr starved and fed rats rose in parallel with increased medium substrate concentration. 3. Formation of [14C]glucose from I mM (14C]alaninc was similar in liver and kidney cortex slices and increased in tissues from 24 hr starved compared with fed rat5. With 5 mM (14C]alanine more (14C]glucose was produced by liver than by kidney cortex slices from 24 hr starved rats. Liver ,lices always produced more [l4C]lactate and less [14C]-CO2 from [l 4C]alanine than kidney cortex slices. 4. It is proposed that under physiological conditions, the kidney~ cortex actively participates in glucose product10n from alanine.