Transport Across Amphibian Skin

Erlij, David; Ussing, Hans H.

doi:10.1007/978-3-642-46364-8_6

Cited by 9 publications

(8 citation statements)

References 137 publications

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“…The permeability properties of cellular junctions also may depend on the osmotic and hydration status of cells which, in skin, will be determined by the total water barrier properties, their location, and their interaction with blood capillaries and the environment at the skin surface. Changes in cellular volume can alter active transport as well as the structure of intercellular spaces (Erlij and Ussing, 1978). Moreover, the osmotic flow of water within epithelia can induce dilation or collapse of the lateral extracellular spaces, depending on the flow direction, and thereby affect diffusion in a manner that is independent of cellular shrinking or swelling.…”

Section: Cellular Junctions and The Extracellular Diffusion Pathwaymentioning

confidence: 99%

Water relations of tetrapod integument

Lillywhite

2006

Journal of Experimental Biology

262

240

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Section: Cellular Junctions and The Extracellular Diffusion Pathwaymentioning

confidence: 99%

Water relations of tetrapod integument

Lillywhite

2006

Journal of Experimental Biology

262

240

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“…During sloughing there is a decrease in the short-circuit current (indicative of active ion transport activity), transepithelial potential (indicative of the electrical potential difference between the two sides of the cell membrane) and skin resistance (Larsen, 1970(Larsen, , 1971aNielsen and Tomilson, 1970). These changes seem to result from the physical shedding of the slough, as they are initiated by the separation of the slough from the underlying skin layer (reviewed in Erlij and Ussing, 1978). However, these studies artificially induced sloughing through the administration of hormones such as aldosterone (Nielsen, 1969;Larsen, 1971a), which can potentially create unrealistic electrophysiological data (relative to natural or spontaneous sloughing), because aldosterone also acts to regulate ion and water reabsorption in the kidneys (Garty, 1986;Eaton et al, 2001) and skin (Bentley, 2002), and increases protein synthesis in the bladder and skin (Crabbé and de Weer, 1964).…”

Section: Introductionmentioning

confidence: 99%

“…As there are physical and physiological changes in the skin associated with sloughing (Larsen, 1976;Erlij and Ussing, 1978), does the change in skin function cause temporary electrolyte disruption in the animal's homeostasis (e.g. blood biochemistry), or does the skin actively upregulate expression of epithelial ion transporters (e.g.…”

Section: Introductionmentioning

confidence: 99%

Living with a leaky skin: upregulation of ion transport proteins during sloughing

Cramp

Franklin

2017

Journal of Experimental Biology

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Amphibian skin is a multifunctional organ providing protection from the external environment and facilitating the physiological exchange of gases, water and salts with the environment. In order to maintain these functions, the outer layer of skin is regularly replaced in a process called sloughing. During sloughing, the outermost layer of the skin is removed in its entirety, which has the potential to interfere with skin permeability and ion transport, disrupting homeostasis. In this study, we measured, in vivo, the effects of sloughing on the cutaneous efflux of ions in toads Rhinella marina kept in freshwater conditions. We also measured transepithelial potential, cutaneous resistance, active ion transport and the distribution, abundance and gene expression of the key ion transport proteins sodium-potassium ATPase (NKA) and epithelial sodium channel (ENaC) during sloughing. We hypothesised that the increase in transepithelial efflux of ions during sloughing is a consequence of increased permeability and/or a reduction in the abundance or expression of cutaneous ion transport proteins, resulting in disruption of internal ion homeostasis. There was a significant increase in sodium and chloride efflux during sloughing in R. marina. However, although in vitro skin resistance decreased after sloughing, active sodium transport increased commensurate with an increase in NKA and ENaC protein abundance in the skin. These changes in skin function associated with sloughing did not affect the maintenance of internal electrolyte homeostasis. These results suggest that during sloughing, amphibians actively maintain internal homeostasis by increasing cutaneous rates of ion uptake.

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“…The time calibration is the same for both tracings. Nearly all the transepithelial Na current crosses the apical border of the epithelium through amiloridesensitive channels (for reference, see Erlij & Ussing, 1978). To determine whether or not the increase in I, caused by quinacrine was due to activation of the amiloride-sensitive Na pathway we measured, in 6 experiments, the effects of amiloride on the quinacrine stimulation of I.C.…”

Section: Resultsmentioning

confidence: 99%

Prostaglandin release mediates drug‐induced stimulation of sodium transport in frog skin: the effects of quinacrine

Erlij

Gersten

1985

British J Pharmacology

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1 Quinacrine markedly increased the release ofprostaglandin E2 (PGE2) into the basolateral solution of the bullfrog skin from a control value of 32.7 ± 21.7 pg per 20 min period to a stimulated value of 8593.1 ± 4112.3 pg per 20min period.2 Quinacrine increased the amiloride-sensitive short circuit current from 20.7 ± 2.1 IA cm-2 to 45.4± 6.5ftAcm2.3 The stimulatory effects of quinacrine on both short circuit current and prostaglandin release were blocked in skins pretreated with indomethacin (10-6M). 4 Quinacrine did not block either the stimulation of the short circuit current or the increase in PGE2 release caused by the calcium ionophore, ionomycin. 5 These results suggest: (a) the release of PGE2 and the stimulation of the short circuit current caused by quinacrine are linked since blocking PGE2 release inhibits the stimulation of the short circuit current; (b) given the complexity of its actions, quinacrine is a poor tool to examine whether the effects of a given agent are mediated through the activation of endogenous phosopholipases. In addition our results taken together with other findings in the literature suggest that there is a diverse group of compounds that stimulate transepithelial sodium transport by releasing PGE2.

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Transport Across Amphibian Skin

Cited by 9 publications

References 137 publications

Water relations of tetrapod integument

Water relations of tetrapod integument

Living with a leaky skin: upregulation of ion transport proteins during sloughing

Prostaglandin release mediates drug‐induced stimulation of sodium transport in frog skin: the effects of quinacrine

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