L-ascorbic acid regulates growth and metabolism of renal cells: improvements in cell culture.
The addition of L-ascorbic acid 2-phosphate (AscP) to primary cultures of rabbit renal proximal tubular cells (RPTC) grown under improved culture conditions resulted in an extended growth phase and increased cellular density (1.3-fold increase in monolayer DNA and protein contents). AscP reduced glycolysis, increased net lactate consumption by 38%, and stimulated net glucose production by 47%. Basal O2 consumption increased by 39% in RPTC grown in the presence of AscP and was equivalent to that in freshly isolated proximal tubules. AscP increased ouabain-sensitive O2 consumption (81%) and Na(+)-K(+)-ATPase activity (2.5-fold), which suggested increased active Na+ transport. Addition of AscP increased Na(+)-dependent glucose uptake by 43% and brush-border enzyme marker activities by 46%. It is concluded that supplementation of media with AscP further improves RPTC culture conditions by promotion of cellular growth and stimulation of in vivo-like respiration, lactate utilization, and net glucose synthesis. These changes are accompanied by an increase in brush-border enzyme activities and stimulation of active Na+ transport and Na(+)-dependent glucose transport, which demonstrate an improved expression of brush-border membrane functions in RPTC.
Nowak
G
G
Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock 72205-7199, USA.
Schnellmann
R G
RG
D000818:Animals; D001205:Ascorbic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D005260:Female; D007684:Kidney Tubules / Q000166:cytology / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects*; D011817:Rabbits
C011669:ascorbate-2-phosphate; D001205:Ascorbic Acid; D010100:Oxygen