AJP - Cell Physiology, Vol 254, Issue 3 C450-C458, Copyright © 1988 by American Physiological Society
Lectin-gold labeling of glycoconjugates in normal and Brattleboro rat papilla: effect of vasopressin
P. Weyer, D. Brown and L. Orci
Institute of Histology and Embryology, University Medical Centre, Geneva, Switzerland.
Some reports suggest that the plasma membrane glycocalyx of collecting duct
epithelial cells, as well as interstitial glycoconjugates, may be involved
in vasopressin action and urinary concentration. In view of this, we have
used the lectin-gold technique to map and quantify Helix pomatia lectin
(HPL)-binding sites in the inner medulla of kidneys from normal Long-Evans
rats, vasopressin-deficient Brattleboro rats, and Brattleboro rats treated
for up to 5 wk with exogenous vasopressin. The results show that the
labeling of epithelial cell plasma membranes from collecting ducts and thin
limbs of Henle is not different between normal and Brattleboro rats, and
the labeling is not modified by chronic vasopressin treatment. In contrast,
the heavy interstitial labeling seen in normal rats is virtually absent
from Brattleboro rats, but it is progressively restored by chronic
vasopressin treatment of Brattleboro rats. These results show that
vasopressin does not modify HPL-binding glycoconjugates on epithelial cell
plasma membranes, but that vasopressin treatment has a major effect on
HPL-binding glycoconjugates in the medullary interstitium.
