Pflügers Archiv

, 452:300

Phenotype analysis of mice deficient in the peptide transporter PEPT2 in response to alterations in dietary protein intake

  • Isabelle M. Frey
  • Isabel Rubio-Aliaga
  • Martina Klempt
  • Eckhard Wolf
  • Hannelore Daniel
Epithelial Transport

DOI: 10.1007/s00424-005-0042-5

Cite this article as:
Frey, I.M., Rubio-Aliaga, I., Klempt, M. et al. Pflugers Arch - Eur J Physiol (2006) 452: 300. doi:10.1007/s00424-005-0042-5

Abstract

The peptide transporter PEPT2 mediates cellular uptake of di- and tripeptides driven by an inwardly directed electrochemical proton gradient. In mammals PEPT2 is found in a variety of organs such as kidney, lung, brain, enteric nervous system, and mammary gland. Highest expression levels are observed in renal proximal tubules where PEPT2 contributes to reabsorption of filtered di- and tripeptides. To assess the physiological importance of the transporter in overall metabolism, we have generated a Pept2−/− mouse line that lacks a functional PEPT2 protein. Here we present data on body weight, organ weights, and blood pressure. Mice were then fed diets containing either 10, 20, or 30% (w/w) protein, and food and water intake rates as well as plasma and urine parameters were determined. In spite of PEPT2 expression in a variety of tissues, only subtle phenotypic changes were observed. Male PEPT2 null mice displayed lower bodyweight and lower relative heart weight, whereas, relative kidney weight was lower in female Pept2−/− mice. No differences were found in blood pressure. When fed diets with different protein contents, Pept2−/− mice adapted food intake to dietary protein content with higher consumption rates on low protein and reduced food intake rates on the high protein diet.

Keywords

Peptide transportBody weightOrgan weightBlood pressureClinical–chemical parametersUrine parameters

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • Isabelle M. Frey
    • 1
  • Isabel Rubio-Aliaga
    • 2
  • Martina Klempt
    • 3
  • Eckhard Wolf
    • 3
  • Hannelore Daniel
    • 1
  1. 1.Molecular Nutrition Unit, Institute of Nutritional SciencesTechnical University of MunichFreising-WeihenstephanGermany
  2. 2.Institute of Experimental Genetics, GSF-National Research Center for Environment and HealthNeuherbergGermany
  3. 3.Institute of Animal Breeding and Biotechnology, Gene CenterLudwig Maximilian University of MunichMunichGermany