Prolactin inhibits corticoid-induced differentiation of active Na+ transport across cultured frog tadpole skin

1995 ◽  
Vol 269 (5) ◽  
pp. C1326-C1331 ◽  
Author(s):  
M. Takada ◽  
H. Yai ◽  
K. Takayama-Arita
Keyword(s):  
Acetylcholine Receptor ◽  
Inhibitory Action ◽  
Blood Group Antigen ◽  
The Other ◽  
Basal Cells ◽  
Na Transport ◽  
Adult Type ◽  
Frog Tadpole ◽  
Antigen A ◽  
Tadpole Skin

Active Na+ transport differentiates in larval bullfrog skin cultured with corticoids. After 2 wk in culture, the epidermis became positive against human blood group antigen A, the marker for the adult-type cells of the epidermis, but was negative to the antibody against the acetylcholine receptor, the marker for the larval-type epidermis. Amiloride (10(-5) M) did not inhibit the differentiation of active Na+ transport. On the other hand, in skin cultured with prolactin (2 micrograms/ml), the epidermis remained negative against antigen A and positive against acetylcholine receptor, and the differentiation of active Na+ transport was inhibited. Thyroid hormone did not antagonize the inhibitory action of prolactin on this transport differentiation. Prolactin affected the basal cells of the larval epidermis and inhibited development of corticoid-induced adult features in the epidermis.

Prolactin antagonizes the corticoid-promoted development of adult-type epidermis in cultured larval bullfrog skin.

1996 ◽  
Vol 199 (12) ◽  
pp. 2573-2578
Author(s):  
M Takada ◽  
H Yai ◽  
S Komazaki ◽  
K Takayama-Arita
Keyword(s):  
Blood Group ◽  
Human Blood ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Blood Group Antigen ◽  
Basal Cells ◽  
Adult Type ◽  
Human Blood Group ◽  
Larval Type ◽  
Antigen A

EDTA-treated larval bullfrog skin, in which apical and skein cells had been removed and only basal cells remained, was cultured in one of four media. These contained either aldosterone (Aldo) or a mixture of Aldo, hydrocortisone (HC) and corticosterone (C), each either supplemented with prolactin (PRL) or lacking PRL. Skin cultured with Aldo alone or with the corticoid mixture (Aldo + HC + C) developed an adult-type epidermis: (i) both types of skin reacted to human blood group antigen A, a marker for the adult-type epidermis of bullfrog skin; (ii) amiloride decreased the short-circuit current Isc in these skin preparations, but acetylcholine (ACh) had no effect on the Isc. It seemed to make little difference to the results whether the skin was cultured with Aldo or with the corticoid mixture. PRL antagonized the action of Aldo and induced the development of a larval-type epidermis in both skin preparations: (i) the skin preparations did not react to human blood group antigen A; (ii) acetylcholine and amiloride each stimulated Isc in these preparations. Since ACh and amiloride each stimulated the Isc in skin with apical cells, ACh/amiloride-stimulated channels may be located on these cells.

Corticoid-induced differentiation of amiloride-blockable active Na+ transport across larval bullfrog skin in vitro

1995 ◽  
Vol 268 (1) ◽  
pp. C218-C226 ◽  
Author(s):  
M. Takada ◽  
H. Yai ◽  
K. Takayama-Arita
Keyword(s):  
Transport System ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Basal Cells ◽  
Na Transport ◽  
Induced Differentiation ◽  
Adult Type ◽  
In Vivo Experiments

The hormone-induced differentiation of an active Na+ transport across larval bullfrog skin during metamorphosis was investigated in vitro and in vivo. In in vitro experiments, EDTA-treated larval dorsal skin from which apical cells were removed was used. Even in the absence of thyroid hormone, corticoids induced the differentiation. Although aldosterone was the most potent hormone, hydrocortisone or corticosterone was also effective. Prolactin inhibited the corticoid-induced differentiation. The differentiation of the transport system coincided almost exactly with the appearance of adult features of the epidermis, namely, the epidermis at 7 days carried the human blood group antigen A, a specific molecular marker of adult-type bullfrog epidermis. The transport system appeared to develop in cells that had been newly generated from basal cells. On the contrary, in in vivo experiments, the effect of amiloride on the short-circuit current of the skin of tadpoles raised in the presence of aldosterone was very small, suggesting that a mechanism exists to inhibit the ability of aldosterone to induce the differentiation of the transport system in vivo.

scholarly journals Effects of Mg and Ca on the side dependencies of Na and K on ouabain binding to red blood cell ghosts and the control of Na transport by internal Mg.

1976 ◽  
Vol 67 (5) ◽  
pp. 547-561 ◽  
Author(s):  
H H Bodemann ◽  
J F Hoffman
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Inhibitory Action ◽  
External Surface ◽  
The Other ◽  
Na Transport ◽  
Ouabain Binding ◽  
Conformational States ◽  
Binding Rate ◽  
Relative Affinity

The effect of alteration in the concentration of internal Mg on the rate of ouabain binding to reconstituted human red blood cell ghosts has been evaluated as well as the effect of Mgi on Na:Na compared to Na:K exchange. It was found that the dependence of the rate of ATP-promoted ouabain binding on the combined presence of Nai and Ko which occurs at high [Mg]i is lost when the concentration of Mgi is lowered. The sensitivity of the external surface for Ko is also changed since Ko can now inhibit the ouabain binding rate in the absence of Nai; on the other hand Nao at low [Mg]i can stimulate ouabain binding indicating that the relative affinity of the outside surface for Nao has either increased or that for Ko has decreased or both. Thus the effects of changes in [Mg]i result in a change in the side-dependent actions of Na and K and emphasize the possible difficulties of interpreting results obtained on systems lacking sidedness. Mgi was found to be required for Pi-promoted ouabain binding and that the inhibitory action of Nai increased as [Mg]i was increased. In addition, Ca was found to be most effective in inhibiting the rate of ATP-promoted ouabain binding when Na and K were present together than when either was present alone. Na:K exchange was found to be more sensitive to the concentration of Mgi than Na:Na exchange; at low [Mg]i Na:K exchange could be stimulated without changing the extent of Na:Na exchange. These results are consistent with the idea that conformational states of the pump complex are directly influenced by [Mg]i.

A Weak Example of the Blood Group Antigen A

Vox Sanguinis ◽  
1961 ◽  
Vol 6 (2) ◽  
pp. 151-156 ◽  
Author(s):  
B. P. L. Moore ◽  
P. H. Newstead ◽  
Joanne Johnson
Keyword(s):  
Blood Group ◽  
Blood Group Antigen ◽  
Antigen A

Ultrastructural Characteristics of Capillaries Entering and Leaving the Stria Vascularis

1986 ◽  
Vol 95 (3) ◽  
pp. 309-312 ◽  
Author(s):  
Kensuke Watanabe
Keyword(s):  
Horseradish Peroxidase ◽  
Basal Cell ◽  
Stria Vascularis ◽  
The Other ◽  
Spiral Ligament ◽  
Perivascular Spaces ◽  
Basal Cells ◽  
Vascular Flow ◽  
Cell Layers ◽  
Ultrastructural Characteristics

Capillaries entering and leaving the stria vascularis were surrounded by layers of basal cells and fibrocytes. The entering capillaries were surrounded by one or two thin basal cells, while the leaving capillaries were surrounded by four or five thicker and interdigitated basal cell layers. Moreover, the layers surrounding the leaving capillaries persisted further into the spiral ligament. Two kinds of filaments were observed in the basal cells, one thin and the other thick. Capillaries were observed to leak horseradish peroxidase before they entered and after they left the stria vascularis. Although the reaction product of horseradish peroxidase was observed in all perivascular spaces of leaving capillaries, very little or no reaction product was observed around some entering capillaries. It is speculated that the layers of basal cells and fibrocytes around entering and leaving capillaries control the vascular flow out of the stria vascularis, although the layers around leaving capillaries may be more contractile than those around entering capillaries.

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