Vasopressin-elicited refractoriness of the response to vasopressin in toad urinary bladder

1981 ◽  
Vol 240 (6) ◽  
pp. F551-F557 ◽  
Author(s):  
J. S. Handler ◽  
A. S. Preston
Keyword(s):  
Urinary Bladder ◽  
Adenylate Cyclase ◽  
Water Permeability ◽  
Recovery Period ◽  
Ringer Solution ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Toad Urinary Bladder ◽  
Camp Phosphodiesterase ◽  
Prolonged Incubation

Incubation of the urinary bladder of Bufo marinus with high concentrations of vasopressin produces refractoriness to subsequent stimulation of water permeability by low concentrations of vasopressin. Development of refractoriness is directly dependent on concentration of vasopressin and duration of incubation with the hormone. Refractoriness develops in the absence of transepithelial water flow, is evident following a 2-h recovery period of incubation in hormone-free Ringer solution, and is reversed after prolonged incubation in hormone-free Ringer solution. Development and reversal of refractoriness is not altered by actinomycin D or cycloheximide. The steps at which refractoriness develops have been identified partially. Under different conditions, refractoriness involves: 1) reduced vasopressin-sensitive adenylate cyclase activity, 2) reduced epithelial cell cAMP accumulation in response to vasopressin the absence of demonstrable change in vasopressin-sensitive adenylate cyclase activity, cAMP phosphodiesterase activity, or loss of cAMP into the Ringer solution, and 3) refractoriness of water permeability response to exogenous cAMP.

Release of cyclic AMP by toad urinary bladder

1975 ◽  
Vol 228 (3) ◽  
pp. 954-958 ◽  
Author(s):  
S Urakabe ◽  
JS Handler ◽  
J Orloff
Keyword(s):  
Epithelial Cells ◽  
Urinary Bladder ◽  
Cyclic Amp ◽  
Cell Membrane ◽  
Water Permeability ◽  
Ringer Solution ◽  
Mucosal Surface ◽  
Toad Urinary Bladder ◽  
Solution Bathing

Cyclic AMP accumulates in the Ringer solution bathing the toad urinary bladder in vitro. At least 4 times more cyclic AMP is released into the solution bathing the serosal surface than into the solution bathing the mucosal surface. Most of the cyclic AMP originates in the epithelial cells rather than the stroma. Vasopressin increased the content of cyclic AMP in the epithelial cells and increases the amount of cyclic AMP in the Ringer solution. Since there is not an increase in medium cyclic AMP when cell cyclic AMP levels are increased by theophylline, it is suggested that theophylline may reduce the permeability of the cell membrane to cyclic AMP. Finally, it is demonstrated that 10 mM NaF increase the amount of cyclic AMP in the epithelial cells and in the solution bathing the bladder, but block the effect of vasopressin on water permeability, presumably at a step subsequent to the formation of cyclic AMP.

Cholera toxin enhances adenylate cyclase-dependent transport in toad urinary bladder

1987 ◽  
Vol 252 (4) ◽  
pp. F621-F626
Author(s):  
B. S. Hoch ◽  
S. D. Levine
Keyword(s):  
Urinary Bladder ◽  
Adenylate Cyclase ◽  
Cholera Toxin ◽  
Water Flow ◽  
Culture Media ◽  
Phosphodiesterase Inhibitor ◽  
Toad Urinary Bladder ◽  
Urea Transport ◽  
Prolonged Incubation ◽  
Stimulation Of

Cholera toxin (CT) irreversibly ADP-ribosylates and activates the nucleotide-stimulatory (Ns) subunit of adenylate cyclase in many tissues, thereby eliciting cyclase-dependent functions. Although earlier studies performed at room temperature could not demonstrate CT-stimulated water transport in toad urinary bladder, subsequent work in other tissues has emphasized the need for incubation at 35-37 degrees C to effect ribosylation and the subsequent physiological effects. We found that incubating tissues with amphibian culture media, rather than Ringer solution, maintained tissue viability at this higher temperature and permitted prolonged incubation with CT. At 37 degrees C, in the presence of 0.1 mM phosphodiesterase inhibitor (1-methyl-3-isobutylxanthine, MIX), 0.2-200 nM mucosal CT caused a dose-dependent but submaximal enhancement of water flux and urea transport. Elimination of MIX from the bath diminished subsequent CT-induced stimulation, supporting a role for adenosine 3',5'-cyclic monophosphate (cAMP) as mediator of the CT effect. The increased water flow was stable for greater than 1 h after removal of CT from the bath, consistent with irreversible stimulation of the cyclase. Mucosal CT stimulated transport to a greater degree than serosal CT, paralleling the pattern seen in the intestine, which is compatible with passage of the toxin's a subunit across the cell to the serosal membrane cyclase. Exposure of the tissue's mucosal surface to GM1 ganglioside, (the natural receptor for the CT b subunit) yielded maximal stimulation of water flow and near-maximal urea transport, presumably by increasing CT's binding to the cell membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

Persistent stimulation of adenylate cyclase and urea transport by an AVP photolabel

1985 ◽  
Vol 249 (1) ◽  
pp. C84-C88 ◽  
Author(s):  
P. Eggena ◽  
C. L. Ma ◽  
F. Fahrenholz ◽  
I. L. Schwartz
Keyword(s):  
Adenylate Cyclase ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Covalent Attachment ◽  
Toad Urinary Bladder ◽  
Target Tissue ◽  
Previous Suggestion ◽  
Urea Permeability ◽  
Vasopressin Receptors ◽  
Stimulation Of

The effects of a photoaffinity label for arginine vasopressin receptors, [Phe2, Phe(p-N3)3]AVP (N3-AVP), on urea permeability and adenylate cyclase activity have been investigated in the toad urinary bladder. This compound, when activated by ultraviolet light, induced a maximal and persistent increase in the urea permeability of the intact bladder and a persistent increase in the adenylate cyclase activity of toad bladder epithelial cell homogenates. Covalent attachment of the analogue to target tissue during photolysis was equivalent at 4 and 20 degrees C. Bladders exposed to N3-AVP in the presence of AVP during photolysis were substantially less permeable to urea than controls that had been exposed to N3-AVP alone. These findings constitute further evidence in support of our previous suggestion that N3-AVP binds covalently to AVP receptors and, in addition, demonstrates that N3-AVP evokes a persistent increase in adenylate cyclase activity which, in turn, triggers a persistent increase in bladder permeability to urea.

Cytochemical Evidence for Presynatic β-Adrenergic Regulation of Secretion in the Developing Rat Submandibular Gland

1977 ◽  
Vol 35 ◽  
pp. 430-431
Author(s):  
L.S. Cutler
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Submandibular Gland ◽  
Neonatal Rat ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Parotid Glands ◽  
Adrenergic Agonist ◽  
Rat Submandibular Gland

Many studies previously have shown that the B-adrenergic agonist isoproterenol and the a-adrenergic agonist norepinephrine will stimulate secretion by the adult rat submandibular (SMG) and parotid glands. Recent data from several laboratories indicates that adrenergic agonists bind to specific receptors on the secretory cell surface and stimulate membrane associated adenylate cyclase activity which generates cyclic AMP. The production of cyclic AMP apparently initiates a cascade of events which culminates in exocytosis. During recent studies in our laboratory it was observed that the adenylate cyclase activity in plasma membrane fractions derived from the prenatal and early neonatal rat submandibular gland was retractile to stimulation by isoproterenol but was stimulated by norepinephrine. In addition, in vitro secretion studies indicated that these prenatal and neonatal glands would not secrete peroxidase in response to isoproterenol but would secrete in response to norepinephrine. In contrast to these in vitro observations, it has been shown that the injection of isoproterenol into the living newborn rat results in secretion of peroxidase by the SMG (1).

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