Letter | Published:

Purine Catabolism, a Source of Endogenously Formed Urea in Homogenates of Amphibian Kidney

Naturevolume 199pages602603 (1963) | Download Citation



CLASSICAL thinking holds that the bulk of urea formed in the body is derived from reactions of the Krebs–Henseleit cycle1 occurring in the liver of mammals and of amphibia2. Although the cycle is incomplete in mammalian kidney due to a relative lack of ornithine transcarbamylase and of carbamyl phosphate synthetase3, the enzymatically catalysed pathway, citrulline+aspartatearginineurea+ornithine provides a potential source of urea in kidney cells.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Krebs, H. A., and Henseleit, K., Hoppe-Seyl. Z., 210, 33 (1932).

  2. 2

    Cohen, P. P., and Brown, G. W., jun., in Comparative Biochemistry, 2, 161, edit. by Florkin, M., and Mason, H. S. (New York City: Academic Press, 1960).

  3. 3

    Jones, M. E., Anderson, A. D., Anderson, C., and Hodes, S., Arch. Biochem. Biophys., 95, 499 (1961).

  4. 4

    Cedrangolo, F., Della Pietra, G., Cittadini, Papa S., and DeLorenzo, F., Nature, 195, 708 (1962).

  5. 5

    Braunstein, A. E., Severina, S., and Babskaja, J. E., Biokhimia, 21, 738 (1956).

  6. 6

    Carlisky, N. J., Brodsky, W. A., Huang, K. C., and Munsey, E., Physiologist, 5, 115 (1962).

  7. 7

    Conway, E. J., Biochem. J., 29, 2755 (1935).

  8. 8

    Umbreit, W. W., in Metabolic Maps, 2, 142 (Minneapolis, Minn.: Burgess Publishing Co., 1960).

Download references

Author information


  1. Departments of Medicine and Pharmacology, and Bio-Transport Unit, University of Louisville School of Medicine, Louisville, 2, Kentucky



  1. Search for WILLIAM A. BRODSKY in:

  2. Search for NESTOR J. CARLISKY in:

About this article

Publication history

Issue Date




By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.