We have previously shown that shaking the culture plates (SHAKE) of ra
bbit renal proximal tubule cells (RPTC) to maintain adequate aeration
increased aerobic metabolism and decreased the induction of glycolysis
compared to RPTC cultured under standard conditions (STILL). However,
glycolysis in SHAKE RPTC remained elevated compared to glycolysis in
proximal tubules in vivo. In the present study the contribution of cul
ture medium sugar composition and concentration to glycolytic metaboli
sm was assessed in RPTC. SHAKE and STILI, RPTC cultured in 5 mM glucos
e contained lactate levels equivalent to the respective SHAKE and STIL
L RPTC cultured in standard culture medium which contains 17.5 mM gluc
ose. Similarly, the activity of lactate dehydrogenase was unchanged by
lowering the medium glucose concentration. Substituting 5 mM galactos
e for 5 mM glucose in the culture medium significantly reduced the lac
tate content of both SHAKE and STILL RPTC but had no effect on lactate
dehydrogenase activity. Cell growth was equivalent under all culture
conditions. Sensitivity to mitochondrial inhibition was determined for
each culture condition by measuring cell death after exposure to the
respiratory inhibitor antimycin A. The results showed a hierarchy of s
ensitivity to antimycin A (5 mM galactose SHAKE > 5 mM glucose SHAKE >
17.5 nM glucose SHAKE = 17.5 mM glucose STILL), which was generally i
nversely correlated with the level of glycolysis as measured by lactat
e content (17.5 mM glucose STILL > 17.5 mM glucose SHAKE = 5 mM glucos
e SHAKE > 5 mM galactose SHAKE).