The Journal of Physiological Sciences

, Volume 62, Issue 6, pp 461–468 | Cite as

Adaptive transport of folic acid across renal epithelia in folate-deficient rats

  • Nissar Ahmad Wani
  • Jyotdeep KaurEmail author
Original Paper


Folate (vitamin B9) is an essential vitamin for a wide spectrum of biochemical reactions; however, unlike bacteria and plants, mammals are devoid of folate biosynthesis and thus must obtain this cofactor from exogenous sources. The activities of folate transporters on the kidneys play an important role in conserving folate excretion and reabsorption across the apical membrane of the renal proximal tubules. The different transport system activities may become identifiable in response to external stimuli, such as folate availability and exposure to chemotherapeutic agents. We have explored the effect of folate deficiency on the activity and expression of folate transporters in rat kidneys. Wistar rats were fed a folate-containing diet (2 mg folic acid kg−1 diet) or a folic acid-free diet over a 3-month period, and mechanisms of folate transport were studied in renal brush border membrane vesicles and basolateral membrane vesicles. The renal folate uptake process is saturable and pH dependent, and it involves the folate receptor and reduced folate carrier (RFC) systems and possibly the proton coupled folate transporter (PCFT) system. We found that folate deficiency increased the renal brush border membrane and basolateral folate uptake by increasing the number of transporter molecules. The observed up-regulation of mRNA expression was also associated with a significant increase in RFC and PCFT expression at the protein level.


Renal folate uptake PCFT RFC Folate transporters Folate deficiency Rats 



The financial assistance from Indian council of Medical Research, New Delhi, India is highly acknowledged.

Conflict of interest

The authors declare that they have no competing interests.


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Copyright information

© The Physiological Society of Japan and Springer 2012

Authors and Affiliations

  1. 1.Department of BiochemistryPostgraduate Institute of Medical Education and ResearchChandigarhIndia

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