Vasopressin decreases immunogold labeling of apical actin in the toad bladder granular cell.
Studies with the confocal microscope have shown that arginine vasopressin (AVP) depolymerizes F-actin in the apical region of the toad bladder granular cell. However, the resolution of the fluorescence microscope is not great enough to reveal the exact pattern of depolymerization or the relative extent to which microvillar and subapical membrane actin pools contribute to overall depolymerization. We have developed an electron microscopic immunogold method that shows a significant decrease in immunogold labeling of actin in the region just below the apical membrane, with the decrease most pronounced in regions adjacent to the microvilli. There was no significant change of immunogold labeling within the microvilli themselves. Our studies show a reorganization of the actin cytoskeleton in the region of the granular cell, where water channel-carrying vesicles are positioned and fuse in response to AVP.
Gao
Y
Y
Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461.
Franki
N
N
Macaluso
F
F
Hays
R M
RM
D000199:Actins / Q000378:metabolism*; D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology*; D002024:Bufo marinus; D002462:Cell Membrane / Q000378:metabolism; D005260:Female; D006098:Granulocytes / Q000378:metabolism* / Q000648:ultrastructure; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D014018:Tissue Distribution; D001743:Urinary Bladder / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure
D000199:Actins; D001127:Arginine Vasopressin