L-ascorbic acid regulates growth and metabolism of renal cells:
improvements in cell culture .
Nowak, Grayna, and Rick G. Schnellmann.
University of Arkansas for Medical Sciences, Department of
Pharmacology and Toxicology, 4301 West Markham St., Little Rock, AR
72205-7199
APStracts 3:0230C, 1996.
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 QO2
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 QO2 (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.
Received 7 November 1995; accepted in final form 25 June 1996.
APS Manuscript Number C677-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 25 July 1996