HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 560/1/267    most recent jphysiol.2004.068403v1 Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Monks, J. Articles by Neville, M. C Search for Related Content PubMed PubMed Citation Articles by Monks, J. Articles by Neville, M. C

¹ Department of Physiology and Biophysics, University of Colorado Health Sciences Center, Denver, CO 80262
² Department of Pediatrics, National Jewish Medical and Research Center, Denver, CO 80206, USA

Murine milk contains 18 mg ml^–1 serum albumin, a concentration equal to that in the serum of the lactating mouse. We examined cellular transport using in vivo methods in the mouse. At steady state the specific activity of ¹²⁵I-albumin injected into the blood stream was equal in plasma and whey, confirming that milk albumin is extra-mammary in origin. Fluorescent albumin crossed the gland from basolateral surface to lumen via cytoplasmic vesicles, but was not transported in the apical to basal direction. Albumin was segregated from transferrin at the basal surface of the epithelial cells and did not colocalize with either caveolin-1 or -2. Vesicular transport was not disrupted by filipin providing additional evidence that, unlike the vascular endothelium, caveoli are not involved. Cytoplasmic albumin was localized to vesicles containing IgA and transport was disrupted by agents that interfere with clathrin-mediated endocytosis. Together, these findings provide evidence that albumin is transported across the mammary epithelium by the same pathway as immunoglobulin. The possibility that the massive transfer of albumin into mouse milk is mediated by fluid phase transport is considered.

(Received 29 May 2004; accepted after revision 29 July 2004; first published online 5 August 2004)
Corresponding author M. C. Neville: Department of Physiology and Biophysics, Room 2802-2, Box C240, University of Colorado Health Sciences Center, Denver, CO 80262, USA. Email: peggy.neville{at}uchsc.edu

This article has been cited by other articles:

				J. R. Sabah, B. D. Schultz, Z. W. Brown, A. T. Nguyen, J. Reddan, and L. J. Takemoto Transcytotic Passage of Albumin through Lens Epithelial Cells Invest. Ophthalmol. Vis. Sci., March 1, 2007; 48(3): 1237 - 1244. [Abstract] [Full Text] [PDF]

				N. Lambot, P. Lybaert, A. Boom, J. Delogne-Desnoeck, A.M. Vanbellinghen, G. Graff, P. Lebrun, and S. Meuris Evidence for a Clathrin-Mediated Recycling of Albumin in Human Term Placenta Biol Reprod, July 1, 2006; 75(1): 90 - 97. [Abstract] [Full Text] [PDF]