Urologic Oncology 5 (2000) 234–237
1078-1439/00/$ – see front matter © 2000 Elsevier Science Inc. All rights reserved.
Glycosaminoglycan content of human bladders:
a method of analysis using cold-cup biopsies
Matthew M. Poggi
, Peter A. S. Johnstone*
, R. Jeffrey Conner
Radiation Oncology Branch, National Cancer Institute, Bethesda, MD 20892, USA
Radiation Oncology Division, Naval Medical Center, San Diego, CA 92134-5000, USA
Urology Department, Naval Medical Center, San Diego, CA 92134-5000, USA
Radiation Oncology Division, University of California, San Diego, CA 92103, USA
Received 27 August, 1999; received in revised form 26 January, 2000; accepted 1 March, 2000
A glycocalyx layer composed of glycosaminoglycans (GAGs) and other molecules lines the transitional epithelium of the urinary blad-
der. This layer forms a barrier between the transitional cells and urinary bladder environment and is believed to help prevent the adher-
ence of bacteria, minerals and carcinogens. Investigators postulate that quantitative and/or qualitative defects in the GAG component
may be responsible for a spectrum of acute and chronic disease processes ranging from urinary tract infections to cancer. While the pres-
ence of epithelium GAGs has been confirmed biochemically and histochemically, few rigorous characterizations have been performed.
This study establishes the methodology and feasibility of using routine cold-cup biopsies from cadaveric human bladders for GAG analy-
sis and establishes baseline contents of the sulfated and non-sulfated GAGs in the urinary bladder glycocalyx. Using detergent extraction,
the GAGs from cold-cup biopsies (
34) from four cadaveric bladders were isolated. The isolates were subjected to two colorimetric as-
says to quantify both sulfated and non-sulfated GAGs. The nonsulfated GAG content of the bladder epithelium ranged from 2.15
mmol/kg of dry, defatted bladder. The sulfated GAG content ranged from 2.00
mmol/kg of dry, de-
fatted bladder. These values are consistent with reports found in the literature using electrophoresis on full-thickness human bladder
specimens. The GAG content of human bladder epithelium can be readily and accurately characterized from cold-cup biopsy samples.
Our future plans involve using this routinely used technique to analyze samples from live control and disease-state bladders thereby dem-
onstrating any quantitative and/or qualitative differences in GAG constituents. © 2000 Elsevier Science Inc. All rights reserved.
Bladder; Glycosaminoglycan; Assay
Previous investigators have demonstrated by electron
microscopy [1,2] and histochemical staining  that a gly-
cocalyx composed of proteoglycans and their smaller con-
stituents, glycosaminoglycans (GAGs), lines the transitional
epithelium of the human urinary bladder. GAGs are rela-
tively large polysaccharides found in the ground substance
of connective tissue in all vertebrates. Because of their
highly negative charge at physiological pH, GAGs bind
water, typically via their sulfate group, to the exclusion of
other cations such as calcium, barium and hydrogen .
With the proposal over twenty years ago that GAGs form a
“Blood-Urine Barrier” , it has been postulated that some
inflammatory bladder pathologies may arise as a result of a
defective in the GAG component of the uroepithelium gly-
cocalyx. Although treatments based on this model have
been clinically tested, few rigorous studies of bladder GAGs
have been performed. Prior investigations are limited in
scope and methodology. As a first step in systematically an-
alyzing and evaluating the role of uroepithelium GAG con-
stituents, our study establishes the methodology and fea-
sibility of using routine, small cold-cup biopsies from
cadaveric human bladders. A baseline quantitative analysis
of sulfated and non-sulfated GAGs was also performed.
Qualitative characterization of the various sub-types of
GAGs within the GAG layer is currently underway using
barium acetate electrophoresis and densitometry with speci-
mens from live patients.
* Corresponding author. Tel.:
: email@example.com (P. Johnstone).
The views expressed in this article are those of the authors and do not
reflect the official policy or position of the Department of the Navy,
Department of Defense, or the US Government.
Presented in part as a poster at the meeting of the American Radium
Society, Hawaii, April 17–21, 1999.