AJP - Regulatory, Integrative and Comparative Physiology, Vol 239, Issue 5 505-R508, Copyright © 1980 by American Physiological Society
Comparison of transcutaneous permeability in skins of larval and adult salamanders (Ambystoma tigrinum)
P. J. Bentley and G. F. Baldwin
The electrical properties and transcutaneous movements of Na, Cl, and water
were compared (in vitro) in skins of larval and adult forms of Ambystoma
trigrinum. Larval skin had a mean transcutaneous potential difference of 6
mV (inside positive) in adults it was 50 mV. Short-circuit current (Isc)
was, respectively, about 2 microA x cm-2 and 20 microA x cm-2. Electrical
resistances were similar. Passive effluxes of Na and Cl were similar in
both forms but Na influx (active direction) was much greater in the adult.
Diffusional permeability to water was less in the larval salamander skin.
Influx of Na and Isc were increased by vasotocin in the adult but not
larval skin. Water permeability was unaffected by vasotocin in either form.
The properties of the premetamorphic skin are compared to those of two
other urodele amphibians.
