Response of dermal melanophores to epinephrine after removal of the epidermal barrier

1. 1. Comparison of methods for selectively removing epidermis from goldfish integument demonstrated that the use of EDTA provided efficient epidermis removal, excellent melanophore viability and good dermal cell preservation. 2. 2. Photometric measurement of melanophore response to epinephrine and to goldfish melanophore Ringer solution permitted quantitation of the degree of melanosome dispersion. 3. 3. Removal of the epidermis produced a tenfold increase in melanophore sensitivity to epinephrine and decreased post-treatment recovery rate. Thus, the epidermis is a diffusion barrier of considerable magnitude. 4. 4. Lipophores (xanthophores) and iridophores were unresponsive to epinephrine treatment (10 μg/ml) indicating that epinephrine is not involved in the normal hormonal control of these pigment cells.