Affiliations: Agharkar Research Institute, Pune, India
Note: [] Address for correspondence: Dr. V.V. Agte, Agharkar Research
Institute, G. G. Agarkar Road, Pune-411004, India. Tel.: +91 020 5653680; Fax:
+91 020 5651542; E-mail: vaishaliagte@hotmail.com
Abstract: Zinc plays a dual role, as an integral part of metabolic machinery
and in defense against reactive oxygen species. Hepatocytes are important sites
for zinc metabolism for synthesis of zinc metalloproteins and maintaining its
homeostasis. However, the factors influencing post absorptive zinc metabolism
under normal and oxidative stress (OS) conditions are not well understood.
Using rat liver slices, we conducted a series of four in vitro zinc
uptake experiments to study influence of ascorbic acid and folic acid in normal
and oxidative stress conditions with Zn concentrations representing deficient
to excess states (7.7–30.7 millimole/L). Zinc uptakes under OS at these four
zinc levels were lower than the normal conditions. Folic acid showed
significant inhibitory effect on zinc uptake under both normal and OS
conditions in a dose response manner. Nevertheless, dose response of ascorbic
acid at four zinc levels indicated its marked enhancing effect under OS
condition. Differences in zinc uptake trend lines between the normal and OS
conditions for interaction of both the vitamins narrowed down as the zinc
levels increased. Our results suggest that folic acid causes inhibitory effect,
while ascorbic acid may be protective in OS with reference to zinc uptake.
