Acid-base regulation in response to hypercapnia in the lymphatic and circulatory systems of the toad Bufo marinus

1992 ◽  
Vol 170 (1) ◽  
pp. 271-276
Author(s):  
RJ Garland ◽  
DP Toews
Keyword(s):  
Bufo Marinus ◽  
Acid Base ◽  
Toad Bufo

Renal function and acid-base balance in the toad Bufo marinus during short-term dehydration

1986 ◽  
Vol 64 (5) ◽  
pp. 1054-1057 ◽  
Author(s):  
B. L. Tufts ◽  
D. P. Toews
Keyword(s):  
Renal Function ◽  
Bufo Marinus ◽  
Ambient Water ◽  
Acid Base Balance ◽  
Acid Base ◽  
Short Term ◽  
Base Balance ◽  
Toad Bufo ◽  
Normal Acid ◽  
Tubular Component

Specimens of Bufo marinus (L.) were cannulated in both ureters to partition between the regulatory contributions of the kidney and urinary bladder. These bladder-bypassed animals were then exposed to 10 h of dehydration in air and renal function and acid–base balance were assessed. The results indicated that the kidney showed an almost immediate response to dehydration which consisted of a large glomerular and smaller tubular component. Bypassing and emptying of the bladder and the removal of the ambient water had no effect on the animal's ability to maintain normal acid–base balance.

Acid-Base Relationships in the Blood of the Toad, Bufo Marinus: III. The Effects of Burrowing

1979 ◽  
Vol 82 (1) ◽  
pp. 357-365
Author(s):  
R. G. BOUTILIER ◽  
D. J. RANDALL ◽  
G. SHELTON ◽  
D. P. TOEWS
Keyword(s):  
Respiratory Acidosis ◽  
Lung Ventilation ◽  
Progressive Increase ◽  
Bufo Marinus ◽  
Sharp Decline ◽  
Acid Base ◽  
Arterial Blood ◽  
Blood Ph ◽  
Equilibrium Ratio ◽  
Toad Bufo

When Bufo marinus burrows, the skin becomes intimately surrounded by substrate but the nares always remain exposed to the surface air. Upon entering into a state of dormancy the animal hypoventilates and this together with the loss of the skin as a respiratory site results in a rise in arterial blood Pcoco2 despite a probable decline in metabolism. Even though lung ventilation falls, the toad regulates blood pH and the respiratory acidosis is progressively compensated for by a progressive increase in plasma [HCO3-] along the course of an elevated PCOCO2 isopleth. At steady state, the acidosis is fully compensated for by a new equilibrium ratio of HCO3- to PCOCO2 at the same pH as the non-burrowed animal. Arousal from the dormant state at this time results in a marked lung hyperventilation and a sharp decline in body CO2 stores

scholarly journals Acid-base regulation in the toad Bufo marinus during environmental hypoxia

1991 ◽  
Vol 85 (2) ◽  
pp. 217-230 ◽  
Author(s):  
H.-O. Pörtner ◽  
L.M. MacLatchy ◽  
D.P. Toews
Keyword(s):  
Bufo Marinus ◽  
Acid Base ◽  
Environmental Hypoxia ◽  
Toad Bufo

Intracellular pH in the toad Bufo marinus following hypercapnia

1991 ◽  
Vol 161 (1) ◽  
pp. 415-422 ◽  
Author(s):  
G. K. Snyder ◽  
J. R. Nestler
Keyword(s):  
Intracellular Ph ◽  
Bufo Marinus ◽  
Secondary Effects ◽  
Acid Base ◽  
Arterial Pco2 ◽  
Toad Bufo ◽  
Intracellular Acid

We investigated the effects of hypercapnia on intracellular acid-base regulation in brain and liver of the toad Bufo marinus L. After 1 h at 5% CO2, arterial PCO2 increased significantly, from 1.6 +/− 0.04 to 5.7 +/− 0.23 kPa, while brain and liver intracellular pH (pHi) decreased significantly. Reductions in pHi of both tissues were partially compensated by increased levels of bicarbonate. Surprisingly, however, compensation was lower than expected in brain and higher than expected in liver. We suggest that compensation in brain may be limited by secondary effects of bicarbonate loading in this tissue.

scholarly journals Compensation of progressive hypercapnia in the toad (Bufo marinus) and the bullfrog (Rana catesbeiana)

1990 ◽  
Vol 148 (1) ◽  
pp. 293-302
Author(s):  
D. P. Toews ◽  
D. F. Stiffler
Keyword(s):  
Ion Transport ◽  
Rana Catesbeiana ◽  
Bufo Marinus ◽  
Extracellular Ph ◽  
Ion Flux ◽  
Acid Base Balance ◽  
Acid Base ◽  
Base Balance ◽  
Co2 Level ◽  
Toad Bufo

Toads (Bufo marinus L.) and bullfrogs (Rana catesbeiana Shaw) were subjected to a series of 24 h step increases in aerial CO2 (2, 4, 6 and 8%) to assess the degree of extracellular pH compensation at each CO2 level and to ascertain the importance of cutaneous ion transport in this process. Elevation of plasma [HCO3-] occurs during the 24 h period, with the bullfrogs showing a greater ability to compensate at each step. There was no indication that a [HCO3-] threshold of 30 mmol l-1 existed in either species, although bullfrogs appeared to have a greater compensatory potential when exposed to the higher levels of CO2. The results of the ion flux experiments suggest that neither the terrestrial Bufo nor the semi-aquatic Rana use their skin to any great extent for acid-base balance during hypercapnia.

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