Receptor mechanisms in fish chromatophores—II. Evidence for beta adrenoceptors mediating melonosome dispersion in guppy melanophores

Factors Influencing Motile Activities of Fish Chromatophores

“…Healey and Ross (1966) stated, however, that it had no effects on the melanophores of Phoxinus minnows. Miyashita and Fujii (1975) also found that it had no pigment-dispersing effect on the melanophores of guppies.…”

“…Using isolated pieces of fin from the top minnow Gambusia affinis, Colley and Hunt (1974) also demonstrated the presence of beta-receptors on the melanophores. Miyashita and Fujii (1975) found that a number of sympathomimetic amines, including epinephrine, could cause the reversible dispersion of pigment in the melanophores of split pieces of tail fin from the guppy Poecilia reticulata. The effect was especially remarkable when alpha-adrenoceptors were blocked.…”

Control of organelle transport in melanophores: Regulation of CA2+ and cAMP levels

“…Epinephrine also binds beta adrenoceptors, which can induce dispersion in various chromatophores [Miyashita and Fujii, 1975;Katayama et al, 19901. By binding both classes of adrenergic receptors, epinephrine may generate conflicting signals that result in a reduced rate of aggregation.…”

Skin Color Control of the Red Sea Bream (Pagrus major)

“…The major hormones that regulate the chromatosome movements on the fish skin are the melanophorestimulating hormones and melanin-concentrating hormones from the intermediate lobe of the pituitary (3,5,6). Many physiological and pharmacological studies have revealed that rapid chromatosome movements (dispersion and aggregation) in melanophores are also controlled via autonomic neurons (3,(7)(8)(9)(10)(11). Therefore, the rapid skin colour change after killing of cultured sea bream is thought to be mainly due to the rapid dispersion of chromatosomes in melanophores elicited by handling and killing stresses.…”