P. Veranic et K. Jezernik, Succession of events in desquamation of superficial urothelial cells as a response to stress induced by prolonged constant illumination, TISSUE CELL, 33(3), 2001, pp. 280-285
The effect of moderate stress induced by prolonged illumination was analyse
d on urothelial cells of female mouse urinary bladders at ultrastructural a
nd cytochemical levels. This study demonstrates that the urothelium respond
s to moderate stress with desquamation which involves two subsequent steps.
The first step includes a local detachment of tight junctions and conseque
ntly the loss of the permeability barrier leading to expanded intercellular
spaces among urothelial cells. During the second step, the disjunction of
desmosomes accompanied by exocytosis of lysosomal enzymes (NADPase) in the
intercellular space results in exfoliation of superficial cells. It is evid
ent that moderate stress elicits an enhanced desquamation of only superfici
al cells by a subsequent dysfunction of first tight junctions and after tha
t adherens-type junctions. A rapid restoration of the new tight junctions p
revents a long-term malfunction of the blood-urine barrier. (C) 2001 Harcou
rt Publishers Ltd.