THE EFFECTS OF NEUROHYPOPHYSIAL EXTRACTS ON WATER TRANSFER ACROSS THE WALL OF THE ISOLATED URINARY BLADDER OF THE TOAD BUFO MARINUS

1958 ◽  
Vol 17 (3) ◽  
pp. 201-209 ◽  
Author(s):  
P. J. BENTLEY
Keyword(s):  
Urinary Bladder ◽  
Bladder Wall ◽  
Water Transfer ◽  
Passive Movement ◽  
Bufo Marinus ◽  
Metabolic Inhibitors ◽  
Osmotic Gradient ◽  
High Concentrations ◽  
Toad Bufo

SUMMARY 1. An in vitro preparation of the urinary bladder of Bufo marinus is described. 2. Small doses of 'Pituitrin' markedly increase the rate of water transfer across the bladder wall when the solutions inside the bladder are hypotonic. 3. Passive movement is small and increases slightly with increases in the osmotic gradient across the bladder wall. It is unaffected by changes in substrate levels or any of the metabolic inhibitors tested except for cyanide which increases it in some cases. 4. The vasopressor neurohypophysial fraction is more active than the oxytocic one in increasing water transfer across the bladder wall. 5. The increase in water transfer depends on an intact oxygen supply and sufficient glucose or pyruvate. 6. Iodoacetate, malonate, cyanide, 2–4-dinitrophenol, and bubbling 5% CO2+95% O2 through Ringer's solution inhibit the water transfer in response to neurohypophysial extract. 7. Diamox is only an effective inhibitor at very high concentrations. 8. The possible mechanism of the water transfer is discussed.

THE EFFECTS OF IONIC CHANGES ON WATER TRANSFER ACROSS THE ISOLATED URINARY BLADDER OF THE TOAD BUFO MARINUS

1959 ◽  
Vol 18 (4) ◽  
pp. 327-333 ◽  
Author(s):  
P. J. BENTLEY
Keyword(s):  
Urinary Bladder ◽  
Potassium Concentration ◽  
Choline Chloride ◽  
Bladder Wall ◽  
Water Transfer ◽  
Bufo Marinus ◽  
Serosal Side ◽  
Ionic Changes ◽  
Toad Bufo

SUMMARY 1. The effects of ionic changes in the bath fluids on water transfer across an in vitro preparation of the urinary bladder of the toad Bufo marinus were investigated. 2. Calcium was necessary to maintain the normal low permeability of the bladder to water in the absence of Pituitrin. Magnesium, strontium and manganese but not barium could substitute for calcium. 3. With low concentration of calcium there was a reduction in the water transfer across the bladder wall in response to Pituitrin and no other divalent ion could substitute for calcium. 4. Exclusion of potassium from the serosal side of the bladder reduced the water transfer in the presence of Pituitrin. Increase in potassium concentration above normal levels also inhibited the response to hormone. When no Pituitrin was present there was no change in water loss from the bladder with alterations in potassium concentration. Absence of potassium from the epithelial side of the bladder had no effect whether Pituitrin was present or not. 5. The presence of sodium on the epithelial side increased the water transfer in response to Pituitrin and neither lithium, choline nor potassium could substitute for it. Replacement of 50% of the sodium chloride on the serosal side of the bladder by choline chloride decreased the water transfer in response to Pituitrin.

DIRECTIONAL DIFFERENCES IN THE PERMEABILITY TO WATER OF THE ISOLATED URINARY BLADDER OF THE TOAD, BUFO MARINUS

1961 ◽  
Vol 22 (1) ◽  
pp. 95-100 ◽  
Author(s):  
P. J. BENTLEY
Keyword(s):  
Urinary Bladder ◽  
Electric Current ◽  
Opposite Direction ◽  
Water Movement ◽  
Water Transfer ◽  
Bufo Marinus ◽  
Osmotic Gradient ◽  
Serosal Side ◽  
Toad Bufo

SUMMARY 1. If the osmotic gradient is favourable vasopressin increases the rate of water movement across the bladder of the toad from the serosal to the epithelial side, which is the opposite direction to that seen physiologically. 2. Water transfer down an osmotic gradient is 1·8 times more rapid towards the serosal than towards the epithelial side. Vasopressin increases this difference so that water is moving 4·9 times as rapidly to the serosal side. Iodoacetate reduces this effect of vasopressin. 3. If water is moving down an osmotic gradient towards the anode, a higher electric current increases the water movement in the presence, but not in the absence, of vasopressin. If water movement is taking place towards the cathode an increased current has no effect. 4. With vasopressin present, absence of sodium on the epithelial side of the bladder reduces water transfer down an osmotic gradient towards the serosal side, but has no effect on water movement down an osmotic gradient in the opposite direction.

Active transport of calcium across the urinary bladder and colon of the toad Bufo marinus

1983 ◽  
Vol 245 (1) ◽  
pp. R91-R94 ◽  
Author(s):  
C. J. Rosoff ◽  
G. F. Baldwin ◽  
P. J. Bentley
Keyword(s):  
Urinary Bladder ◽  
Active Transport ◽  
Bufo Marinus ◽  
Calcium Flux ◽  
Metabolic Inhibitors ◽  
Net Flux ◽  
Calcium Exchange ◽  
Toad Bufo

Unidirectional fluxes of calcium were measured (in vitro) across the urinary bladder and colon of the toad Bufo marinus in the absence of electrochemical gradients. A net calcium flux was observed in each tissue, but the polarity differed; it occurred from the mucosal (luminal) to the serosal side of the colon and from the serosal to mucosal (urinary) side of the bladder. The active transport in each tissue appeared to involve different mechanisms; that across the colon exhibited a sodium dependence, possibly involving a sodium-calcium exchange, but this was not seen in the urinary bladder. The net flux in the latter was, however, abolished by metabolic inhibitors, possibly reflecting a role of a calcium-adenosine triphosphatase mechanism. The results are discussed in relation to the calcium metabolism of this amphibian.

scholarly journals THE FINE STRUCTURE OF THE URINARY BLADDER OF THE TOAD, BUFO MARINUS

1963 ◽  
Vol 16 (1) ◽  
pp. 53-72 ◽  
Author(s):  
Jae Kwon Choi
Keyword(s):  
Fine Structure ◽  
Urinary Bladder ◽  
Bladder Wall ◽  
Single Layer ◽  
Bufo Marinus ◽  
Cell Junctions ◽  
Basal Region ◽  
Basal Cells ◽  
Migratory Cells ◽  
Toad Bufo

The urinary bladder of the toad (Bufo marinus) was studied with both the light and the electron microscope. The bladder wall consists of epithelium, submucosa, and serosa. In the epithelium, four different cell types were recognized on the basis of their fine structure and staining properties with several different dyes. These four were designated as granular cells, mitochondria-rich cells, mucous cells, and basal cells. In addition, migratory cells of a different type were found in the basal region of the epithelium. The luminal surface of the epithelial cells presents irregular microvilli and is coated by PAS-positive material which has been further investigated by histochemical procedures and radioautography. Included is a description of the fine structural details of cell membranes, cell junctions, and intracellular components. The submucosa consists of a delicate stroma of fibroblasts and collagen fibers and also contains blood and lymph vessels, unmyelinated nerves, migratory cells, and smooth muscle cells. The serosa consists of a single layer of serosal (mesothelial) cells which form an uninterrupted covering of the viscus. Possible pathways of sodium and water transport across the bladder wall are discussed.

OSMOTIC INHIBITION OF THE NATRIFERIC RESPONSE OF THE TOAD URINARY BLADDER TO VASOPRESSIN

1975 ◽  
Vol 67 (1) ◽  
pp. 119-125
Author(s):  
P. J. BENTLEY
Keyword(s):  
Urinary Bladder ◽  
Water Movement ◽  
Short Circuit ◽  
Electrical Potential ◽  
Short Circuit Current ◽  
Toad Bladder ◽  
Toad Urinary Bladder ◽  
Electrical Potential Difference ◽  
Osmotic Gradient

SUMMARY The electrical potential difference and short-circuit current (scc, reflecting active transmural sodium transport) across the toad urinary bladder in vitro was unaffected by the presence of hypo-osmotic solutions bathing the mucosal (urinary) surface, providing that the transmural flow of water was small. Vasopressin increased the scc across the toad bladder (the natriferic response), but this stimulation was considerably reduced in the presence of a hypo-osmotic solution on the mucosal side, conditions under which water transfer across the membrane was also increased. This inhibition of the natriferic response did not depend on the direction of the water movement, for if the osmotic gradient was the opposite way to that which normally occurs, the response to vasopressin was still reduced. The natriferic response to cyclic AMP was also inhibited in the presence of an osmotic gradient. Aldosterone increased the scc and Na+ transport across the toad bladder but this response was not changed when an osmotic gradient was present. The physiological implications of these observations and the possible mechanisms involved are discussed.

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