The alkali metal ions in isolated systems and tissues

Ussing, Hans H.

doi:10.1007/978-3-642-49246-4_1

Cited by 76 publications

(65 citation statements)

References 599 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Cl-is secreted against an electrochemical gradient and the ratio of the unidirectional Cl-fluxes does not correspond to that predicted by the flux-ratio equation (Ussing, 1960). These data suggest active Cl-transport across the teleost gill.…”

Section: Discussionmentioning

confidence: 64%

Active chloride transport in the in vitro opercular skin of a teleost (Fundulus heteroclitus), a gill‐like epithelium rich in chloride cells

Degnan¹,

Karnaky²,

Zadunaisky³

1977

The Journal of Physiology

194

View full text Add to dashboard Cite

K. J. DEGNAN AND OTHERS net Cl-blood side to seawater side flux of 162-8 isA/cm2 which was not statistically different (P > 0.70) from the mean short-circuit current of 158-6 + 163 ,uA/cm2 for these flux studies. The mean Na+ blood side to seawater side flux was 32-2 + 3-3 ,uA/cm2 and the mean Na+ seawater side to blood side flux was 34-8 + 4-1 isA/cm2, resulting in no significant (P > 0*20) net flux of this cation. Similar results were obtained with short-circuited epithelia of seawater-adapted fish when bathed on both sides with Ringer and gassed with 95 % 02/5 % CO2.5. Ouabain (105 M), furosemide (10-3 M), thiocyanate (10-2 M), adrenaline (1I0 M), and anoxia (100 % N2) decreased the short-circuit current 92*7, 85-0, 45-3, 62-6, and 83'3 % respectively. Theophylline (104 M) stimulated the short-circuit current 54-9 %. Increasing the HC03-concentration in the bathing solutions had a stimulatory effect on the short-circuit current and the potential difference across epithelia from seawater-adapted fish.6. The opercular epithelia of freshwater-adapted F. heteroclitU8, when bathed on both sides with Ringer, displayed a mean short-circuit current of 94-1 + 10 4 #sA/cm2, a mean transepithelial potential difference of 14-8 + 1*9 mV (blood side positive), and a mean d.c. resistance of 169-0 + 14-0 Q. cm2 (mean + S.E. of mean; n = 20). Isotope flux studies across these short-circuited epithelia revealed a net Cl-blood side to freshwater side flux of 95-2 + 16-1 ,uA/cm2 and no significant net flux of Na+.7. The opercular epithelia of 200 % seawater-adapted F. heteroclitus, when bathed on both sides with Ringer, displayed a mean short-circuit current of 33-5 + 8-5 IzA/cm2, a mean transepithelial potential difference of 10*5 + 2*5 mV (blood side positive), and a mean transepithelial d.c. resistance of 440 7 + 62*6 Q.cm2 (mean + S.E. of mean n = 18). Isotope flux studies across these short-circuited epithelia revealed a net Cl-blood side to seawater side flux of 96-2 + 51*5 ,uA/cm2 and a net Na+ blood side to seawater side flux of 65'3 + 28-6 ,uA/cm2.

show abstract

Section: Discussionmentioning

confidence: 64%

Active chloride transport in the in vitro opercular skin of a teleost (Fundulus heteroclitus), a gill‐like epithelium rich in chloride cells

Degnan¹,

Karnaky²,

Zadunaisky³

1977

The Journal of Physiology

194

View full text Add to dashboard Cite

show abstract

“…Antidiuretic hormone (ADH) stimulates short-circuit current in frog skin by an action on the outer membrane of the transporting cells (Ussing, 1960;Curran, Herrera & Flanigan, 1963). Interrelationships between ADH and amiloride were therefore examined in the hope that they might provide information on the site and mechanism of action of amiloride.…”

Section: Resultsmentioning

confidence: 99%

“…The estimation of this parameter from Ussing's work equation (Ussing, 1960) is beset with a number of uncontrollable variables (for example the presence of exchange diffusion and sodium movement along shunt paths (Ussing & Windhager, 1964;Civan, Kedem & Leaf, 1966)) which reduce the accuracy of the method. It is therefore not justifiable to base firm conclusions on this evidence alone.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of amiloride on active sodium transport by the isolated frog skin: evidence concerning site of action

Salako

Smith

1970

British J Pharmacology

View full text Add to dashboard Cite

Summary1. Amiloride reduces short-circuit current and potential difference across the isolated frog skin. 2. Isotopically measured sodium influx and efflux are diminished. 3. Total electrical conductance and partial sodium conductance are diminished, the reduction in total conductance being entirely accounted for by the reduction in partial sodium conductance. 4. The effect of antidiuretic hormone (ADH), cyclic 3'5'-adenosine monophosphate (cyclic AMP) and theophylline can be antagonized by pretreatment with amiloride but the antagonism can be abolished by increasing the concentration of these compounds. 5. Amiloride has no effect on oxygen consumption in concentrations which inhibit sodium transport. However, it prevents the stimulatory effect of ADH on oxygen consumption.6. The results are consistent with an action of amiloride at the passive outside membrane of the transporting cells of isolated frog skin.

show abstract

“…The net flux (Jnet) was calculated as the average efflux minus the average influx. The predicted flux ratios were calculated with Ussing's (1960) equation, the average p.d. for the paired preparations, and ion activities based on the activity coefficients extrapolated from the data of Robinson & Stokes (1959).…”

Section: Short-circuit and Open-circuit Experimentsmentioning

confidence: 99%

Open‐circuit sodium and chloride fluxes across isolated opercular epithelia from the teleost Fundulus heteroclitus.

Degnan¹,

Zadunaisky²

1979

The Journal of Physiology

View full text Add to dashboard Cite

2. The mean predicted Na+ flux ratio was 0-94 + 0-08 and the observed ratio was 1-14+0-12 (n = 15; mean+s.E. of mean). The difference in these means was not significant (P > 0-20). The mean predicted Cl-flux ratio was 11-4 + 0-9 and the mean observed ratio was 1-38 + 0-27 (n = 10). The difference in these means was significant (P < 0-001).3. Ouabain, at 10-6 M in the serosal solution, produced a significant (P < 0-01) reduction in the Na+ efflux while having no significant (P > 0-40) effect on the Na+ influx. The agreement between the predicted (1.70 + 0-14) and observed (1-72 + 0-18) Na+ flux ratios after ouabain treatment suggested that this effect could be completely attributed to the depolarization of the epithelium secondary to ATPase inhibition. 4. fl-adrenergic activation by isoprenaline stimulated the Cl-efflux 24-2 % and ot-adrenergic activation by noradrenaline inhibited the Cl-efflux 66-5 %. These changes occurred oppositely to those predicted by the changes in the electrical gradient produced by these agents, while the changes in the Cl-influxes corresponded to the electrical changes. Short-circuit experiments confirmed these effects on the Cl-efflux and the lack of effects on the Cl-influx.5. The results suggested that Na+ was near thermodynamic equilibrium and that the unidirectional fluxes were passive. The effects of a-and /i-adrenergic activation suggested that the active Cl-secretion may be antagonistically regulated by catecholamines.

show abstract

The alkali metal ions in isolated systems and tissues

Cited by 76 publications

References 599 publications

Active chloride transport in the in vitro opercular skin of a teleost (Fundulus heteroclitus), a gill‐like epithelium rich in chloride cells

Active chloride transport in the in vitro opercular skin of a teleost (Fundulus heteroclitus), a gill‐like epithelium rich in chloride cells

Effects of amiloride on active sodium transport by the isolated frog skin: evidence concerning site of action

Open‐circuit sodium and chloride fluxes across isolated opercular epithelia from the teleost Fundulus heteroclitus.

Contact Info

Product

Resources

About