Prolactin increases open-channel density of epithelial Na+ channel in adult frog skin.
The short-term effect of prolactin on the skin of the adult tree frog Hyla arborea japonica was investigated using current-fluctuation analysis. Basolateral application of ovine prolactin (10 microg ml(-1)) (1) increased the amiloride-blockable short-circuit current (SCC) across the skin 2.6+/-0.4-fold and (2) increased the open-channel density (M) of the epithelial Na(+) channel 6.1+/-1.2-fold but decreased the single-channel current i to 0.4+/-0.1 times the control value (N=9). The increase in SCC induced by prolactin was thus due to an increase in M, not i. Apparently, in amphibians prolactin has not only a counteracting effect on metamorphosis but also a stimulatory effect on the development of adult-type features, such as this amiloride-blockable SCC.
Takada
Makoto
M
Department of Physiology, Saitama Medical School, Moroyama, Iruma-gun, Saitama, 3500495 Japan. makokam@saitama-med.ac.jp
Kasai
Miyoko
M
D000704:Analysis of Variance; D000818:Animals; D001001:Anura / Q000378:metabolism*; D004848:Epithelium / Q000378:metabolism; D005712:Galvanic Skin Response / Q000187:drug effects*; D011388:Prolactin / Q000494:pharmacology*; D012867:Skin / Q000378:metabolism*; D015222:Sodium Channels / Q000187:drug effects*
D015222:Sodium Channels; D011388:Prolactin