AJP - Renal Physiology, Vol 260, Issue 3 431-F442, Copyright © 1991 by American Physiological Society
Carbonic anhydrase in turtle bladder mitochondrial-rich luminal and subluminal cells
C. Fritsche, J. G. Kleinman, J. L. Bain, R. R. Heinen and D. A. Riley
Department of Medicine, C.J. Zablocki Veterans Administration Medical Center, Milwaukee, Wisconsin.
Bladders from March-April turtles were processed for carbonic anhydrase
(CA) cytochemically using the method of D.A. Riley, S. Ellis, and J. Bain
(Neuroscience 13: 189, 1984). CA-positive cells comprised 11.1 +/- 0.7% of
mucosal epithelial cells. Microplicated (MP) cells comprised 47.2 +/- 1.8%
of CA-positive cells and displayed at least two distinct staining patterns:
the first was characterized by reaction product that filled the luminal
one-third, including the terminal web and microplicae. These cells
possessed extensive microplicae, a morphological feature of ongoing H+
secretion. The second was characterized by reaction product distributed
throughout cells, excluding the terminal web and microplicae, with greatest
intensity in the luminal one-third below the terminal web. These cells
possessed flattened microplicae, a morphological feature of diminished H+
secretion. Microvillated (MV) cells comprised 6.0 +/- 1.0% of CA-reactive
cells. The basal layer was occupied by 46.8 +/- 1.7% of CA-positive cells,
which were termed subluminal (SL) cells. SL cells were mitochondrial rich
and did not contact the lumen. Extracellular CA staining was common between
the lateral margins of contiguous mitochondrial-rich or
non-mitochondrial-rich cells.
