title: Partition of tissue functions in epithelia: localization of enzymes in "mitochondria-rich" cells of toad urinary bladder.
abstract: The mucosal epithelium of the toad urinary bladder reabsorbs sodium, acidifies the urine, and is responsive to neurohypophyseal hormnones. Mucosal epithelial cells, consisting of two major morphologic cell types, "mitochondria-rich" and "granular," were removed from the bladder and separated by density gradient centrifugation. The mitochondria-rich cells contained three times as much carbonic anhydrase activity as the granular cells. Oxytocin caused a 235 percent increase in the adenosine 3',5'-monophosphate content of mitochondria-rich cells but had no effect on the granular cells. The evidence indicates that the mitochondria-rich cell, which accounts for only 15 percent of the mucosal cells, plays a major role in the mediation of sodium ion and hydrogen ion transport in the toad bladder and is a specific site of action of neurohypophyseal hormones.
mesh_terms: D000818:Animals; D002024:Bufo marinus; D002256:Carbonic Anhydrases / Q000378:metabolism*; D002469:Cell Separation; D002499:Centrifugation, Density Gradient; D000242:Cyclic AMP / Q000032:analysis / Q000494:pharmacology; D003576:Electron Transport Complex IV / Q000378:metabolism*; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects / Q000201:enzymology; D066298:In Vitro Techniques; D008854:Microscopy, Electron; D008928:Mitochondria; D010121:Oxytocin / Q000494:pharmacology; D011863:Radioimmunoassay; D013268:Stimulation, Chemical; D001743:Urinary Bladder / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*
chemical_list: D010121:Oxytocin; D000242:Cyclic AMP; D003576:Electron Transport Complex IV; D002256:Carbonic Anhydrases