Energy dependence of urinary bicarbonate secretion in turtle bladder.

Oliver, Juan A.; Himmelstein, Sharon; Steinmetz, P. R.

doi:10.1172/jci108000

Cited by 21 publications

(8 citation statements)

References 14 publications

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“…Seasonal variability in C1-absorption was also observed by Gonzalez, Shamoo and Brodsky [5]. The results of the present study are entirely consistent with the existence of an anion exchange transport system which depends on metabolic energy [10] and which secretes HCO~-in exchange for absorbed C1- [8].…”

Section: Discussionsupporting

confidence: 92%

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Pathways for bicarbonate transfer across the serosal membrane of turtle urinary bladder: Studies with a disulfonic stilbene

1979

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Bicarbonate is transferred across the serosal (S) membrane of the epithelial cells of the turtle bladder in two directions. Cellular HCO3- generated behind the H+ pump moves this membrane into the serosal solution. This efflux of HCO3- is inhibited by SITS (4-isothiocyano-4'-acetamido-2,2'-disulfonic stilbene). When HCO3- is added to the serosal solution it is transported across the epithelium in exchange for absorbed Cl-. This secretory HCO3- flow traverses the serosal cell membrane in the opposite direction. In this study the effects of serosal addition of 5 x 10(-4) M SITS on HCO3- secretion and Cl- absorption were examined. The rate of H+ secretion was brought to zero by an opposing pH gradient, and 20 mM HCO3- was added to S. HCO3- secretion, measured by pH stat titration, was equivalent to the increase in M leads to S Cl- flux after HCO3- addition. Neither the S leads to M flux of HCO3- nor the M leads to S flux of Cl- were affected by SITS. In the absence of electrochemical gradients, net Cl- absorption was observed only in the presence of HCO3- in the media; under such conditions, unidirectional and net fluxes of Cl- were not altered by serosal or mucosal SITS. H+ secretion, however, measured simultaneously as the short-circuit current in ouabain-treated bladders decreased markedly after serosal SITS. The inhibition of the efflux of HCO3- in series with the H+ pump and the failure of SITS to affect HCO3- secretion and Cl- absorption suggest that the epithelium contains at least two types of transport systems for bicarbonate in the serosal membrane.

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Section: Discussionsupporting

confidence: 92%

“…Mucosal pH was lowered until mucosal acidification was abolished (MpH 4.63+_0.06) so that the rate of bicarbonate secretion could be measured in the absence of hydrogen secretion [10,17]. C136 (New England Nuclear, Boston, Mass.)…”

Section: Methodsmentioning

confidence: 99%

Pathways for bicarbonate transfer across the serosal membrane of turtle urinary bladder: Studies with a disulfonic stilbene

1979

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“…This tolerance is in contrast to the tissue injury observed previously under different anaerobic conditions by Oliver, Himmelstein and Steinmetz (1975) when the serosal solution contained 20 mM HCO~-and was deoxygenated with N2 without CO2. In this previous study the electrical resistance often fell sharply presumably because of the alkalinity imposed on the epithelial ceils by the serosal HCO3 in the absence of metabolic or exogenous CO2.…”

Section: Methodscontrasting

confidence: 87%

Coupling between H+ transport and anaerobic glycolysis in turtle urinary bladder: Effects of inhibitors of H+ ATPase

et al. 1981

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Summary. The coupling between H + transport (Jn)and anaerobic glycolysis was examined in vitro in an anaerobic preparation of turtle urinary bladder. JH was measured as the short-circuit current after Na + transport was abolished with ouabain and by pH stat titration. The media were gassed with N2 and 1% COz (POz<0.5mmHg) and contained 10 mu glucose. Under these conditions, Jn was not inhibited by 3 mM serosal (S) cyanide or by 0.1 mM mucosal (3//) dinitrophenol. Control anaerobic lactate production (Jla~) of 47 bladders was plotted as a function of simultaneously measured Ji+ The slope of Jlac on JH was 0.58+_0.12 with an intercept for Jlac at JH=0 of 0.55 gmol/hr. Values for ~J~ac/g)Jn were determined in groups of individual bladders when JH was inhibited by an opposing pH gradient (0.55 _ 0.16), by acetazolamide (0.58+0.19) and by dicyclohexylcarbodiimide, DCCD (0.58_+0.14). The constancy of 5JIao/fJH indicates a high degree of coupling between JH and Ja~. Since the anaerobic metabolism of glucose produces one ATP for each lactate formed, the 6J~ac/SJI~ values can be used to estimate the stoichiometry of H + translocation. The movement of slightly less than 2 H + ions is coupled to the hydrolysis of one ATP. During anaerobiosis (absence of mitochondrial ATPase function) the acidification pump was not inhibited by M addition of oligomycin but was inhibited by M addition of DCCD and Dio-9, inhibitors of H + flow in the proteolipid portion of H +-translocating ATPases. DCCD inhibited anaerobic JH without change in 6J~/fJH or basal J~,o and,

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“…Because of the one-for-one stoichiometry between Cl reabsorption and HCO3 secretion described above, it was reasonable to assume, along with Leslie et al (1973) and Oliver, Himmelstein & Steinmetz (1975), that Cl reabsorption is driven only in the wake of HCO3 secretion in a non-electrically conductive anion exchange process which is mediated by a metabolically-driven anion exchanger (carrier component) in the apical membrane. If this were the case, Cl reabsorption would have to be dependent upon the presence of HCO3 and conversely, HCO3 secretion would have to be dependent upon the presence of Cl.…”

Section: B Effects Of Sits In Hco3-free or Cl-free Mediamentioning

confidence: 99%

The effects of a disulphonic stilbene on chloride and bicarbonate transport in the turtle bladder.

Brodsky¹,

Durham²,

Ehrenspeck³

1979

The Journal of Physiology

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SUMMARY1. In turtle bladders bathed by Na-free media containing Cl and HCO3, the mucosa is electropositive to the serosa. Serosally applied 4-acetamido-4'-isothiocyano-2,2'-disulphonic stilbene (SITS) reduces the p.d. and I., by 100 %, and reduces the rate of net C1 reabsorption in some bladders but not in others.2. In the absence of exogenous HCOG (Cl present), SITS reduces the p.d. and Ic by 100 %, and reduces the rate of mucosal acidification by 80 %; net C1 reabsorption is not detectable under these HCO3-free bathing conditions.3. In the absence of exogenous C1 (HCO3, present), the mucosa is also electropositive to the serosa and serosally applied SITS reverses the orientation of the p.d. and I8c so that the mucosa becomes electronegative to the serosa.4. This constitutes sufficient evidence for the active, electrogenic secretion of an anion, probably HCO3. These data are explained by an analogue of discrete, electrogenic pumps and paths for the reabsorption of Na, Cl, and HCO3, and the secretion of HCO3.

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Energy dependence of urinary bicarbonate secretion in turtle bladder.

Cited by 21 publications

References 14 publications

Pathways for bicarbonate transfer across the serosal membrane of turtle urinary bladder: Studies with a disulfonic stilbene

Pathways for bicarbonate transfer across the serosal membrane of turtle urinary bladder: Studies with a disulfonic stilbene

Coupling between H+ transport and anaerobic glycolysis in turtle urinary bladder: Effects of inhibitors of H+ ATPase

The effects of a disulphonic stilbene on chloride and bicarbonate transport in the turtle bladder.

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