Abstract
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | Comparative Biochemistry and Physiology A |
| Vol/bind | 148 |
| Udgave nummer | 1 |
| Sider (fra-til) | 55-63 |
| Antal sider | 8 |
| ISSN | 1095-6433 |
| DOI | |
| Status | Udgivet - 2007 |
Bibliografisk note
Keywords: Amphibian skin; Toad; Water uptake; Dehydration; Aquaporins; Seat patch; Blood flowAdgang til dokumentet
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I: Comparative Biochemistry and Physiology A, Bind 148, Nr. 1, 2007, s. 55-63.
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review
}
TY - JOUR
T1 - Vascular aspects of water uptake mechanisms in the toad skin: perfusion, diffusion, confusion
AU - Willumsen, Niels
AU - Viborg, Arne L
AU - Hillyard, Stanley D
N1 - Keywords: Amphibian skin; Toad; Water uptake; Dehydration; Aquaporins; Seat patch; Blood flow
PY - 2007
Y1 - 2007
N2 - Blood cell flow (BCF) in the water absorbing "seat patch" region of toad skin was measured with laser Doppler flow cytometry. BCF of dehydrated toads increased by a factor of 6-8 when water contact was made and declined gradually as toads rehydrated. Water absorption was initially stimulated and declined in parallel with BCF. Water absorption measured during the initial rehydration period did not correlate with BCF and hydrated toads injected with AVT increased water absorption without an increase in BCF indicating the lack of an obligate relation between blood flow and water absorption. Aquaporins 1-3 were characterized by RT-PCR analysis of seat patch skin. AQP 1 was localized in the endothelium of subepidermal capillaries and serves as a pathway for water absorption in series with the apical and basolateral membranes of the epithelium. Dehydrated toads rehydrated more rapidly from dilute NaCl solutions than from deionized water despite the reduced osmotic gradient. BCF of toads rehydrating on 50 mM NaCl was not different than on deionized water and blocking Na+ transport with 100 microM amiloride did not reduce water absorption from 50 mM NaCl. Thus, neither circulation nor solute coupling explains the greater absorption from dilute salt solutions. Rehydration from 10 mM CaCl2 was stimulated above that of DI water by a similar degree as with 50 mM NaCl suggesting the anion might control water permeability of the skin.
AB - Blood cell flow (BCF) in the water absorbing "seat patch" region of toad skin was measured with laser Doppler flow cytometry. BCF of dehydrated toads increased by a factor of 6-8 when water contact was made and declined gradually as toads rehydrated. Water absorption was initially stimulated and declined in parallel with BCF. Water absorption measured during the initial rehydration period did not correlate with BCF and hydrated toads injected with AVT increased water absorption without an increase in BCF indicating the lack of an obligate relation between blood flow and water absorption. Aquaporins 1-3 were characterized by RT-PCR analysis of seat patch skin. AQP 1 was localized in the endothelium of subepidermal capillaries and serves as a pathway for water absorption in series with the apical and basolateral membranes of the epithelium. Dehydrated toads rehydrated more rapidly from dilute NaCl solutions than from deionized water despite the reduced osmotic gradient. BCF of toads rehydrating on 50 mM NaCl was not different than on deionized water and blocking Na+ transport with 100 microM amiloride did not reduce water absorption from 50 mM NaCl. Thus, neither circulation nor solute coupling explains the greater absorption from dilute salt solutions. Rehydration from 10 mM CaCl2 was stimulated above that of DI water by a similar degree as with 50 mM NaCl suggesting the anion might control water permeability of the skin.
U2 - 10.1016/j.cbpa.2006.12.032
DO - 10.1016/j.cbpa.2006.12.032
M3 - Journal article
C2 - 17331768
SN - 1095-6433
VL - 148
SP - 55
EP - 63
JO - Comparative Biochemistry and Physiology A
JF - Comparative Biochemistry and Physiology A
IS - 1
ER -